Abstract: A fixing tool of an auto-tensioner includes inwardly inclined engaging pieces inclined inwardly so as to be opposed to respective tapered surfaces of a spring seat and a cylinder of the auto-tensioner. The engaging pieces have concave surfaces that contact the tapered surfaces over a circumferentially extending area. This minimizes the deformation of the engaging pieces such that the diametrical distances therebetween increase due to contact with the tapered surfaces when sandwiching the spring seat and the cylinder with the engaging pieces from the axially opposite directions, thereby preventing the fixing tool from coming off.

Abstract: A fixing tool of an auto-tensioner includes inwardly inclined engaging pieces inclined inwardly so as to be opposed to respective tapered surfaces of a spring seat and a cylinder of the auto-tensioner. The engaging pieces have concave surfaces that contact the tapered surfaces over a circumferentially extending area. This minimizes the deformation of the engaging pieces such that the diametrical distances therebetween increase due to contact with the tapered surfaces when sandwiching the spring seat and the cylinder with the engaging pieces from the axially opposite directions, thereby preventing the fixing tool from coming off.

Abstract: A hydraulic auto-tensioner includes a sleeve having its bottom end press-fitted in a sleeve fitting hole in the bottom surface of a cylinder, a rod having its bottom end slidably fitted in the sleeve, and a return spring mounted between a spring support at the upper portion of the rod and the bottom surface of the cylinder. A pressure chamber communicates with a reservoir chamber through a passage formed between fitting surfaces of the sleeve fitting hole and the sleeve. The passage has a check valve. The rod has a valve fitting hole and a communication passage through which the valve fitting hole communicates with the reservoir chamber. The valve fitting hole has a relief valve. An orifice is formed between a valve hole formed in a valve seat of the relief valve and a valve body to prevent a sharp drop in pressure in the pressure chamber.

Abstract: A hydraulic auto-tensioner includes a cylinder with a sleeve fitting hole, and a sleeve press-fitted therein. A rod has its bottom end slidable in the sleeve. A return spring is mounted between a spring seat at an upper portion of the rod and a bottom surface of the cylinder. An oil passage, with a check valve, is formed between the fitting surfaces of the sleeve fitting hole and the sleeve and communicates the pressure chamber with the reservoir chamber. The rod has a valve fitting hole open to its bottom surface, and an oil passage communicating the valve fitting hole with the reservoir chamber. A relief valve, mounted in the valve fitting hole, includes a valve seat with a valve hole having an orifice for restricting the flow rate of oil released from the pressure chamber into the reservoir chamber through the oil passage when the relief valve opens.

Abstract: A hydraulic auto-tensioner includes a plunger fitted to a bottom end portion of a rod so as to be slidable along a radially inner surface of a valve sleeve and a radially outer surface of the rod. The plunger has a bottom plate formed with a valve hole. A first leakage gap is defined between sliding surfaces of the plunger and the valve sleeve, and a second leakage gap of which the flow resistance is lower is defined between sliding surfaces of the plunger and the rod such that while the engine is running normally, oil in a pressure chamber leaks into a reservoir chamber through the second leakage gap, and when starting the engine by actuating a starter/generator, the plunger rises until the valve hole is closed so that oil in the pressure chamber leaks into the reservoir chamber through the first leakage gap.

Abstract: In a fulcrum bearing device for a pulley arm, a sleeve is inserted in a shaft hole formed in a boss portion of a pulley arm, washers are fitted on the outer peripheries of small diameter tube portions formed at the respective end portions of the sleeve, and the sleeve is fixed to an engine block by means of a bolt inserted through the sleeve and tightened, so that the pulley arm is pivotally supported. The shaft hole is formed at its respective end portions with seal receiving recesses having large diameters. Each seal member includes a cylindrical portion provided on its outer peripheral portion and press-fitted in the seal receiving recess, and a radial lip extending obliquely inwardly and provided on the inner periphery of the seal member. The distal end portions of the radial lips are kept in elastic contact with the outer diameter surface of the sleeve.

Abstract: A hydraulic auto-tensioner includes a cylinder with a sleeve fitting hole, and a sleeve press-fitted therein. A rod has its bottom end slidable in the sleeve. A return spring is mounted between a spring seat at an upper portion of the rod and a bottom surface of the cylinder. An oil passage, with a check valve, is formed between the fitting surfaces of the sleeve fitting hole and the sleeve and communicates the pressure chamber with the reservoir chamber. The rod has a valve fitting hole open to its bottom surface, and an oil passage communicating the valve fitting hole with the reservoir chamber. A relief valve, mounted in the valve fitting hole, includes a valve seat with a valve hole having an orifice for restricting the flow rate of oil released from the pressure chamber into the reservoir chamber through the oil passage when the relief valve opens.

Abstract: A hydraulic auto-tensioner includes a plunger fitted to a bottom end portion of a rod so as to be slidable along a radially inner surface of a valve sleeve and a radially outer surface of the rod. The plunger has a bottom plate formed with a valve hole. A first leakage gap is defined between sliding surfaces of the plunger and the valve sleeve, and a second leakage gap of which the flow resistance is lower is defined between sliding surfaces of the plunger and the rod such that while the engine is running normally, oil in a pressure chamber leaks into a reservoir chamber through the second leakage gap, and when starting the engine by actuating a starter/generator, the plunger rises until the valve hole is closed so that oil in the pressure chamber leaks into the reservoir chamber through the first leakage gap.

Abstract: A hydraulic auto-tensioner includes a cylinder with a sleeve fitting hole, and a sleeve press-fitted therein. A rod has its bottom end slidable in the sleeve. A return spring is mounted between a spring seat at an upper portion of the rod and a bottom surface of the cylinder. An oil passage, with a check valve, is formed between the fitting surfaces of the sleeve fitting hole and the sleeve and communicates the pressure chamber with the reservoir chamber. The rod has a valve fitting hole open to its bottom surface, and an oil passage communicating the valve fitting hole with the reservoir chamber. A relief valve, mounted in the valve fitting hole, includes a valve seat with a valve hole having an orifice for restricting the flow rate of oil released from the pressure chamber into the reservoir chamber through the oil passage when the relief valve opens.

Abstract: In a fulcrum bearing device for a pulley arm, a sleeve is inserted in a shaft hole formed in a boss portion of a pulley arm, washers are fitted on the outer peripheries of small diameter tube portions formed at the respective end portions of the sleeve, and the sleeve is fixed to an engine block by means of a bolt inserted through the sleeve and tightened, so that the pulley arm is pivotally supported. The shaft hole is formed at its respective end portions with seal receiving recesses having large diameters. Each seal member includes a cylindrical portion provided on its outer peripheral portion and press-fitted in the seal receiving recess, and a radial lip extending obliquely inwardly and provided on the inner periphery of the seal member. The distal end portions of the radial lips are kept in elastic contact with the outer diameter surface of the sleeve.

Abstract: A hydraulic auto-tensioner includes a cylinder containing hydraulic oil, a rod inserted in the cylinder, and two coupling pieces mounted to the bottom of the cylinder and the top end of the rod, respectively. A support ring is inserted in the mounting hole of each coupling piece, and a bush is inserted in the support ring. One of the radially inner surface of the mounting hole and the radially outer surface of the support ring is a curved surface such that the support ring is alignable. Radially outwardly extending flanges are formed at one end of the support ring and at the other end of the bush such that the flanges axially face the respective end surfaces of the coupling piece with gaps left therebetween. A coupling arrangement is provided between the support ring and the bush which is adapted to engage both the support ring and the bush when the bush is inserted into the support ring, thereby axially inseparably coupling them together.

Abstract: A hydraulic auto-tensioner includes a sleeve having its bottom end press-fitted in a sleeve fitting hole in the bottom surface of a cylinder, a rod having its bottom end slidably fitted in the sleeve, and a return spring mounted between a spring support at the upper portion of the rod and the bottom surface of the cylinder. A pressure chamber communicates with a reservoir chamber through a passage formed between fitting surfaces of the sleeve fitting hole and the sleeve. The passage has a check valve. The rod has a valve fitting hole and a communication passage through which the valve fitting hole communicates with the reservoir chamber. The valve fitting hole has a relief valve. An orifice is formed between a valve hole formed in a valve seat of the relief valve and a valve body to prevent a sharp drop in pressure in the pressure chamber.

Abstract: A hydraulic auto-tensioner includes a cylinder with a sleeve fitting hole, and a sleeve press-fitted therein. A rod has its bottom end slidable in the sleeve. A return spring is mounted between a spring seat at an upper portion of the rod and a bottom surface of the cylinder. An oil passage, with a check valve, is formed between the fitting surfaces of the sleeve fitting hole and the sleeve and communicates the pressure chamber with the reservoir chamber. The rod has a valve fitting hole open to its bottom surface, and an oil passage communicating the valve fitting hole with the reservoir chamber. A relief valve, mounted in the valve fitting hole, includes a valve seat with a valve hole having an orifice for restricting the flow rate of oil released from the pressure chamber into the reservoir chamber through the oil passage when the relief valve opens.

Abstract: A hydraulic auto-tensioner includes a cylinder containing hydraulic oil, a rod inserted in the cylinder, and two coupling pieces mounted to the bottom of the cylinder and the top end of the rod, respectively. A support ring is inserted in the mounting hole of each coupling piece, and a bush is inserted in the support ring. One of the radially inner surface of the mounting hole and the radially outer surface of the support ring is a curved surface such that the support ring is alignable. Radially outwardly extending flanges are formed at one end of the support ring and at the other end of the bush such that the flanges axially face the respective end surfaces of the coupling piece with gaps left therebetween. A coupling arrangement is provided between the support ring and the bush which is adapted to engage both the support ring and the bush when the bush is inserted into the support ring, thereby axially inseparably coupling them together.

Abstract: In a tension adjusting device for an engine accessory driving belt by tightening a bolt 7 threaded into an engine block 8, a fulcrum shaft 6 is fixed. A tension pulley 1 is rotatably supported by a pulley arm 2 pivotally supported about the fulcrum shaft 6. A regulating force of a hydraulic auto-tensioner is applied to the pulley arm 2 to press the tension pulley against the belt B. A washer 10 is disposed between a boss 3 formed on the pulley arm 2 and the head 7a of the bolt 7. The washer 10 has an outer cylindrical portion 11 covering one end of the boss 3. A slinger 12 is mounted on the end of the boss 3 to define a labyrinth 13 between the slinger 12 and the cylindrical portion 11, thereby preventing entry of muddy water and dust into the bearing portion pivotally supporting the pulley arm 2.

Abstract: A tension adjusting device for an engine accessory driving belt is provided which can maintain high sealability in the bearing portion about which a pulley arm supporting a tension pulley pivots for a long period of time. By tightening a bolt 7 threaded into an engine block 8, a fulcrum shaft 6 is fixed. A tension pulley is rotatably supported by a pulley arm 2 pivotally supported about the fulcrum shaft 6. A regulating force of a hydraulic auto-tensioner is applied to the pulley arm 2 to press the tension pulley against the belt B. A washer 10 is disposed between a boss 3 formed on the pulley arm 2 and the head 7a of the bolt 7. The washer 10 has an outer cylindrical portion 11 covering one end of the boss 3. A slinger 12 is mounted on the end of the boss 3 to define a labyrinth 13 between the slinger 12 and the cylindrical portion 11, thereby preventing entry of muddy water and dust into the bearing portion pivotally supporting the pulley arm 2.

Abstract: An auto-tensioner for engine accessories is proposed which can smoothly follow shrinkage and expansion of a belt and which can minimize the amplitude of vibration of the belt. A seal member 13 is mounted to a cylinder 11 at its top open end. A rod 16 slidably extends through the seal member 13. A return spring 21 biases the rod 16 outwardly. A plunger 24 is slidably received in a sleeve 12 having a bottom and received in the cylinder 11, and is connected to the bottom of the rod 16. The plunger 24 has a passage 27 through which a lower pressure chamber 25 and an upper reservoir chamber 26 communicate with each other. A check valve 28 is provided at the passage 27. A return chamber 29 is defined under the sleeve 12 so as to communicate with the reservoir chamber 26. In the bottom of the sleeve 12, a valve hole 31 is formed through which the return chamber 29 communicates with the pressure chamber 25. A relief valve 32 is provided at the valve hole 31.

Abstract: In a swash plate type compressor comprising a piston 4 slidably received in a cylinder bore disposed parallel with the driving shaft and a swash plate 2 obliquely attached to the driving shaft and engaged by the piston 4 through a bearing device, the bearing device comprises a spherical seat 4b composed of a single concave surface formed in the piston 4, and a substantially hemispherical shoe 10 contacting the spherical seat 4b, the outer peripheral surface of the shoe 10 being composed of a skirt portion 12, a top portion 16 having a larger radius of curvature, R2, than that R of the spherical seat 4b, and a transition portion 14 contacting the spherical seat 4b between the skirt portion 12 and the top portion 16 and having a smaller radius of curvature, R3, than that R of the spherical seat 4b.

Abstract: The circuit board of the present invention makes the length of the conductor patterns shorter and improves the electric performance for the high speed signal processing. The circuit board of the present invention, which comprises a substrate, is characterized in that the substrate includes: a first face on which conductor patterns, which will be connected to a semiconductor chip, are formed; a second face on which a plurality of pads, on which terminals are formed, are matrically formed; and plated through holes whose one end are respectively opened in the conductor patterns and whose the other ends are respectively opened in the pads, wherein inner faces of the plated through holes are coated with plating layers so as to respectively electrically connect the conductor patterns with the pad.

Abstract: An object of the present invention, in an idler pulley having a pulley main body formed of steel sheet, is to prevent the pulley main body and the outer ring of a bearing from creeping and the pulley main body from slipping off. An idler pulley according to the invention comprises a pulley main body adapted to have a belt entrained therearound, a ball bearing fitted in the pulley main body, and a shaft member fitted in the inner ring of the ball bearing, wherein a layer of a soft metal whose Young's modulus is lower than those of the pulley main body and the outer ring of the bearing is interposed between the inner surface of the pulley main body of steel sheet and the outer surface of the outer ring of the bearing.