Abstract: In a check valve of the present invention, when a pressure action direction of a fluid on a valve body is assumed to be X, a spring receiving surface that abuts with a seat surface that is at one end in an axial direction of the helical compression spring is made to incline with respect to a surface perpendicular to the pressure action direction X. Accordingly, an urging force of the helical compression spring on the valve body acts obliquely with respect to the pressure action direction X. Thus the valve body is pressed to a side wall surface when the valve is opened, and vibration of the valve body is inhibited. Accordingly, it is possible to embody the invention with an extremely simple structure in which the spring receiving surface is inclined with respect to the surface perpendicular to the pressure action direction X.

Abstract: A transmission member that transmits urging force of a helical spring to a valve body is disposed between the valve body and the helical spring. The transmission member changes a direction of an urging force transmitted to the valve body such that the urging force is oblique to a pressure action direction X. Accordingly, when a check valve is in an open state, the valve body is pressed against a side wall and thus vibration of the valve body is inhibited. Further, when the check valve is in a closed state, an angle ? formed by the direction of the urging force transmitted to the valve body and the pressure action direction X is set to be between 8 degrees and 45 degrees. Accordingly, it is possible to simultaneously realize a fluid path opening/closing function and a valve body vibration inhibition function.

Abstract: In a check valve of the present invention, when a pressure action direction of a fluid on a valve body is assumed to be X, a spring receiving surface that abuts with a seat surface that is at one end in an axial direction of the helical compression spring is made to incline with respect to a surface perpendicular to the pressure action direction X. Accordingly, an urging force of the helical compression spring on the valve body acts obliquely with respect to the pressure action direction X. Thus the valve body is pressed to a side wall surface when the valve is opened, and vibration of the valve body is inhibited. Accordingly, it is possible to embody the invention with an extremely simple structure in which the spring receiving surface is inclined with respect to the surface perpendicular to the pressure action direction X.

Abstract: A transmission member that transmits urging force of a helical spring to a valve body is disposed between the valve body and the helical spring. The transmission member changes a direction of an urging force transmitted to the valve body such that the urging force is oblique to a pressure action direction X. Accordingly, when a check valve is in an open state, the valve body is pressed against a side wall and thus vibration of the valve body is inhibited. Further, when the check valve is in a closed state, an angle &thgr; formed by the direction of the urging force transmitted to the valve body and the pressure action direction X is set to be between 8 degrees and 45 degrees. Accordingly, it is possible to simultaneously realize a fluid path opening/closing function and a valve body vibration inhibition function.

Abstract: A check valve allowing one-way fluid flow is disposed at an outlet side of a pressurizing pump. The check valve includes a valve seat and a valve body for opening and closing a fluid passage in response to a fluid pressure supplied to the check valve. The valve body is biased by a biasing member such as a spring in a direction to close the fluid passage. To suppress vibration of the valve body occurring at its open position due to pulsating fluid pressure supplied from the pump, a biasing force is applied to the valve body in a direction slanted from the fluid pressure-imposing direction. The valve body is pushed against a sidewall by a lateral component included in the biasing force, and thereby the vibration of the valve body is suppressed.

Abstract: A check valve allowing one-way fluid flow is disposed at an outlet side of a pressurizing pump. The check valve includes a valve seat and a valve body for opening and closing a fluid passage in response to a fluid pressure supplied to the check valve. The valve body is biased by a biasing member such as a spring in a direction to close the fluid passage. To suppress vibration of the valve body occurring at its open position due to pulsating fluid pressure supplied from the pump, a biasing force is applied to the valve body in a direction slanted from the fluid pressure-imposing direction. The valve body is pushed against a sidewall by a lateral component included in the biasing force, and thereby the vibration of the valve body is suppressed.

Abstract: In a brake apparatus provided with an actuator for controlling brake fluid pressure applied to a wheel cylinder, a non-return valve disposed in a conduit connected to a master cylinder so as to allow brake fluid to flow toward the master cylinder. The non-return valve includes a ball serving as a valve body which seats on a valve seat formed between a small diameter portion and a large diameter portion in the conduit. After the ball is installed in the large diameter portion of the conduit, an opening part of the large diameter portion is closed by a lid while limiting a movement range of the ball so that a center of the ball does not reach an axis of a conduit perpendicularly connected to the large diameter portion.

Abstract: Electric current supplied to a DC motor and a rotational speed thereof are measured. An inductive voltage is calculated based on a relationship that the elapse of time after the application of a voltage to the DC motor is stopped is proportional to the voltage across the terminals of the DC motor. The electric current supplied to the DC motor when the rotation of the DC motor is locked is measured by applying the voltage to the DC motor when a magnetic pole of a stator of the DC motor is not magnetized. The torque of the DC motor when the rotation of the DC motor is locked is measured based on the electric current supplied to the DC motor and the rotational speed thereof when it rotates, the electric current supplied to the DC motor when the rotation of the DC motor is locked, and the inductive voltage. The torque of the DC motor when the rotation of the DC motor is locked is used to determine the torque characteristics thereof.