Abstract: To provide a small-sized and low-cost proportional solenoid valve which is capable of controlling a bidirectional fluid flow. A core is fixed in a pipe, and a hollow shaft having an extreme end thereof closed by a valve seat and a portion adjacent thereto formed with valve holes is fixed in the core. Within the pipe, there are arranged a hollow cylindrical valve element axially movable using the shaft as a guide and urged in a direction away from the core by a spring, for opening and closing the valve holes, and a plunger, while outside the pipe, there is arranged a solenoid coil. The proportional solenoid valve has a body formed by the pipe, and the component parts for opening and closing the valve are arranged within the pipe, so that it is possible to reduce the size of the proportional solenoid valve, the number of component parts, and machining costs and material costs, which contributes to reduction of costs of the valve.

Abstract: The object of the present invention is to provide a switching valve capable of increasing the opening stroke of a valve operated by a differential pressure while saving space, thereby reducing pressure loss. A first valve is disposed between an inlet port and a first outlet port. A pilot valve is provided between a back pressure chamber for a movable plug that holds a valve sheet disposed in a manner opposed to a valve seat, and the first outlet port, such that the first valve is operated by a solenoid. A second valve is arranged between the inlet port and a second outlet port. A back pressure chamber for a movable plug that holds a valve sheet disposed in a manner opposed to a valve seat and the first outlet port are communicated with each other. The second valve is opened by the differential pressure generated by closing of the first valve, and when the first valve is opened, the second valve is closed by the spring since the differential pressure is reduced to zero.

Abstract: The object of the present invention is to provide a three-way switching valve having a valve mechanism compact in size, and capable of changing a flow of a high-pressure fluid, without internal leakage of the fluid. A compact pilot-operated three-way switching valve changes a flow of a fluid introduced into an inlet port such that the fluid is caused to flow into a first outlet port or a second outlet port. Pressures in pressure-regulating chambers above pistons are selectively guided into a passage by a pilot valve having a pilot valve element, plugs including respective valve seats, and a spring. The passage leads one of the pressures to the first outlet port or the second outlet port via a check valve having valve, and a valve element. The check valve causes a very small amount of fluid permitted to flow so as to keep main valves open and closed, respectively, to flow to the downstream side of an open one of the main valves, whereby internal leakage of fluid is prevented.

Abstract: The object of the present invention is to provide a four-way switching valve which is compact in size and inexpensive. A three-way switching valve having a valve element for connecting a port B to a port A, or to a port D via a sleeve, in a switching manner, and a three-way switching valve having a valve element for connecting a port C to the port A, or to the port D, in a switching manner, and a piston for actuating these three-way switching valves are coaxially arranged within a hollow cylindrical body. A three-way solenoid valve introduces high pressure into a pressure chamber on the upper side of the piston to actuate the valve elements held on the sleeve downward, while the upward actuation is effected with a driving force produced by reducing the pressure in the pressure chamber and configuring guides to have a larger pressure-receiving area than that of a guide.

Abstract: To provide a four-way solenoid valve having a three-way solenoid valve of which non-concentricity between a valve element and a valve hole is small, if any. A core of a three-way solenoid is integrally formed with a refrigerant passage extending axially therethrough, an annular projection forming a valve seat, and a guide for guiding reciprocating motion of a needle forming a valve element. A plug closing a cylinder of a body to define the pressure control chamber is also integrally formed with a valve seat and a guide for guiding reciprocating motion of a needle forming a valve element associated with the valve seat. This causes the needles to be seated on the valve seats associated therewith in respective states guided by the guides substantially concentric with the valve holes, which makes it possible to impart sufficient sealing properties to the valve portions when each valve is closed.

Abstract: To provide a small-sized and low-cost proportional solenoid valve which is capable of controlling a bidirectional fluid flow. A core is fixed in a pipe, and a hollow shaft having an extreme end thereof closed by a valve seat and a portion adjacent thereto formed with valve holes is fixed in the core. Within the pipe, there are arranged a hollow cylindrical valve element axially movable using the shaft as a guide and urged in a direction away from the core by a spring, for opening and closing the valve holes, and a plunger, while outside the pipe, there is arranged a solenoid coil. The proportional solenoid valve has a body formed by the pipe, and the component parts for opening and closing the valve are arranged within the pipe, so that it is possible to reduce the size of the proportional solenoid valve, the number of component parts, and machining costs and material costs, which contributes to reduction of costs of the valve.

Abstract: An expansion valve of the degree-of-supercooling control type can be easily adjusted when assembling the degree of supercooling of a high-pressure refrigerant control to be held constant if an exerting force adjusting member is used for finely adjusting the exerting force. If either a throttling portion or a valve seat is formed with the exerting force adjusting member, a simple and compact design or construction can be achieved.

Abstract: A four-way switching valve free from leakage of a refrigerant. A pressure-regulating chamber is switchably connected to a low-pressure chamber or a high-pressure chamber by a three-way solenoid valve, and a pressure-regulating chamber is communicated with a chamber by a tube. When the three-way solenoid valve connects the pressure-regulating chamber to the low-pressure chamber, a plug is urged by the high pressure, thereby permitting port A and a port B to communicate with each other, while inhibiting the port B and a port D from communicating with each other. The pressure within the chamber is increased to thereby increase the pressure within the pressure-regulating chamber. Consequently, a plug is urged by a piston to thereby inhibit the port A and a port C from communicating with each other, and permitting the port C and the port D to communicate with each other.

Abstract: In a main valve having a solenoid pilot operated valve, a movable core and a hollow plunger are movably received in a sleeve extending from a pressure control chamber through an electromagnetic coil. The plunger is structurally separated from a main valve member. A shaft is slidably received in the plunger. One end of the shaft carries a pilot valve member. A spring engages at the plunger and the shaft such that the free end of the shaft projects a predetermined length beyond an end face of the plunger. As long as the coil is deenergized, the spring separates the pilot valve member from a pilot valve seat. As soon as the coil is energized, the plunger is attracted to the core, the shaft is displaced in relation to the plunger, and the pilot valve member projecting from the lower end of the plunger closes the pilot valve seat. Due to the developing pressure difference, the main valve is closed and kept in a closed state.

Abstract: In a main valve having a solenoid pilot operated valve a movable core and a hollow plunger are movably received in a sleeve extending from a pressure control chamber through an electromagnetic coil. Said plunger is structurally separated from a main valve member. A shaft is slidably received in said plunger. One end of said shaft carries a pilot valve member. A spring engages at said plunger and said shaft such that the free end of said shaft projects a predetermined length beyond an end face of the plunger. As long as said coil is de-energised, said spring separates said pilot valve member from a pilot valve seat. As soon as said coil is energised the plunger is attracted to the core, the shaft is displaced in relation to said plunger, and the pilot valve member projecting from the lower end of said plunger closes said pilot valve seat. Due to a then developing pressure difference said main valve is closed and kept in a closed state.

Abstract: In a four-way directional control valve of simplified construction and reduced manufacturing costs, first and second hollow cylindrical valve elements are arranged coaxially. Adjacent to opposite ends of the valve elements, first and second valve seats and first and second valve closure elements are provided. First and second pressure-regulating chambers are arranged between separator walls of the valve elements and first and second partition walls associated to the first and second valve seats. A pilot valve can be switched between switching positions for introducing high-pressure fluid originating from a first pipe into the first or second pressure-regulating chamber via a common high-pressure passage, a high pressure introducing hole and two pilot holes, respectively, associated to the pressure-regulating chambers.

Abstract: A press brake is provided for performing one or more bending operations on a product, such as a sheet metal part, whereby the selection and laying out the clues necessary for bending the product is facilitated by detecting the kinds and layout of the dies loaded in the press brake. A display device is also provided for displaying the layout of the dies, checking interferences between the product and the dies, and displaying the details and features of the product.

Abstract: To provide a connector for a circuit board in which terminals, before bent, have the same overall length, thereby reducing the cost of the terminals, and also preventing the erroneous mounting of the terminals on a connector housing. Distal end portions of a plurality of terminals are passed through and fixed to a connector housing, and proximal end portions of the plurality of terminals are bent, and are connected to the circuit board. The plurality of terminals, before bent, have the same overall length, and a bent portion of one of the adjacent terminals is disposed closer to the connector housing than a bent portion of the other terminal, and internal bend angle .theta. of the one terminal is larger than an internal bend angle .alpha. of the other terminal, and the proximal end portions or the distal end portions of the adjacent terminals are disposed out of phase with each other.

Abstract: In a multistep bending machine, a movable apron (LA) provided with a movable tool (D) is moved in a multistep manner up and down toward a fixed apron (UA) provided with a fixed tool (P) by a hydraulic system including a novel die-axis drive mechanism (DDM), when a foot switch (FS) is kept depressed.In addition, an interference prevention device (IPA), a bending speed determining device (SDA), a tool distance determining device (TDA), a backgage stopper positioning device (SPA), and a backgage stopper pull-back distance controlling device (PDC) are all incorporated in the bending machine to realize a full automatic multistep bending operation.

Abstract: To detect a line position described on a surface by a simple structure, the line position detecting apparatus comprises a light beam generator including a laser diode, a collimator, a prism, and a mirror; a motor for rotating a laser beam to describe a circular locus on the surface; an encoder for detecting a laser beam angular position; a photosensor for detecting a laser beam reflected from the surface; and a calculator for detecting an angular position at which light beam intensity changes due to the presence of the line at at least one point of intersection between the line and the circular locus and for calculating the point indicated by x-y coordinates on the basis of the diameter of the circular locus and the detected angular position of a line to be detected.

Abstract: In a bending press, the stroke length of a ram member is automatically set based upon conditions such as the angle to be made on a workpiece, the width and configuration of a groove in a lower tool, and the thickness, width and tensile strength of the workpiece. There is also an input device into which the bending conditions are set and a computer for calculating the stroke length of the ram member which is then automatically adjusted. A device for detecting deflections occurring in an overhead beam in the bending press is connected to the computer to compensate for the stroke lengths of the ram member. The press accurately and easily bends sheet-like workpieces into various shapes including those cylindrical and semicircular in cross section.

Abstract: This invention relates to a method and apparatus for adjusting a stroke length of a ram for a press. The stroke length of the ram is adjusted with respect to a base point. The hydraulic pressure level in the acting chanber is also adjusted. The press is generally used for bending metal sheets. By this invention, an optimum stroke length of the ram in the press can be easily determined without experimentally processing and, therefore, wasting sheet metal workpieces.