JPH0623498Y2 - Vehicle speed response valve - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial field of application) The present invention relates to a vehicle speed responsive valve.

(Prior Art) A vehicle speed responsive valve includes a valve element that operates according to a vehicle speed, and opens, closes, and switches an oil passage according to the vehicle speed.

However, the vehicle speed responsive valve that is installed in the back pressure circuit of the flow control valve that keeps the hydraulic pressure supplied by the hydraulic pump constant and adjusts the pressure according to the vehicle speed is the same as when the flow rate is adjusted by a needle valve. In contrast, since a large actuating force is required to operate the valve, generally, a pump dedicated to the vehicle speed response valve that is driven to rotate according to the vehicle speed is provided, and the pressure oil from the pump is used to adjust the valve element to the vehicle speed. Operated, or
In response to a signal from an electric vehicle speed sensor, a proportional solenoid or the like is used to operate the response valve.

(Problems to be solved by the invention) Therefore, the conventional vehicle speed responsive valve has a complicated structure, and there is a problem that the valve body cannot be reliably operated in accordance with the vehicle speed.

The present invention has been devised in view of the above circumstances, and an object of the present invention is to provide a vehicle speed responsive valve that has a simple structure and that can reliably operate a valve element in response to a vehicle speed. There is.

(Means for Solving the Problems) In order to achieve the above-mentioned object, the present invention has the above-mentioned structure in which a back pressure circuit (62a) of a flow control valve (41) for controlling a supply hydraulic pressure for power steering assist is provided. A vehicle speed responsive valve for adjusting the supply hydraulic pressure, which is a rotating member (71) connected to a power transmission system and rotating at a rotational speed corresponding to the vehicle speed, and the rotating member (71) having the rotating member (71). Of the movable member (72) installed so as to be movable substantially in the radial direction, and the rotated member (72) that abuts on the movable member (72) and receives the rotational torque according to the vehicle speed due to the frictional force with the movable member (72). 76), a pressure adjusting valve body (85) which engages with the rotated member (76) and opens and closes the back pressure circuit by the rotation torque of the rotated member (76), and the pressure adjusting valve body (85). Equipped with elastic means (92) (95) for energizing 85) and defining its working pressure.

(Operation) When the rotating member (71) rotates at a speed equal to or higher than a predetermined rotation speed, the centrifugal force causes the frictional force between the movable member (72) and the rotated member (76) to become larger than the elastic force of the elastic means (95). , The valve body (85) is operated to open and close the oil passage. Then, since the centrifugal force of the movable member (72) incorporated in the rotating member (71) which is connected to the power transmission system and rotates at the rotating speed corresponding to the vehicle speed is used to operate the valve body (85), With a simple structure, the valve body (85) can be operated reliably according to the vehicle speed. As a result, the hydraulic pressure of the back pressure circuit of the flow control valve is adjusted, so the hydraulic pressure supplied for power steering assist is adjusted. Can be controlled according to the vehicle speed.

(Embodiment) Hereinafter, a case where one embodiment of the present invention is used in a vehicle power steering device will be described.

FIG. 1 shows a hydraulic circuit diagram of the power steering device.

(1) is an oil pump, (2) is an oil tank, (3) is a control valve, and (4) is a power cylinder.
The suction port (1a) of (1) and the oil tank (2) are connected by the oil passage (6), and the discharge port (1b) of the oil pump (1) and the control valve (3) are connected by the oil passage (7). To do.

The left and right cylinder chambers (12) and (13) defined by the piston (11) of the power cylinder (4) and the control valve (3) are connected to the oil passage (1
4), (15) connect, piston rod of power cylinder (4)
(17) Both ends are connected to the left and right steering wheels via tie rods and the like, and a rack (18) is formed on the piston rod (17).

(21) is the steering wheel
By operating (21), the pinion shaft (22) rolls on the rack (18) and slides on the valve body (24) of the actuating valve (23), and is defined on both sides of the valve body (24). The oil chambers (26) and (27) are respectively connected to the oil chambers (32) and (33) defined on both sides of the valve body (31) of the control valve (3).
It is communicated via (34) and (35).

By operating the steering wheel (21), the valve body (24)
Slide the valve body (31) of the control valve (3) through the oil chambers (26), (27), (32), (33) and the oil passages (34), (35). ,
Power oil is supplied to and discharged from the left and right cylinder chambers (12) and (13) through the oil passages (14) and (15) to the left and right cylinder chambers (12) and (13), and (36) in the figure is the control valve. (3) shows an oil passage connecting the operating valve (23) and the oil tank (2).

(41) is a flow control valve, and the flow control valve (41) is provided in an oil passage (7) connecting the oil pump (1) and the control valve (3).

The flow control valve (41) includes a valve body (43), and the flow control valve (41)
The oil chamber (45) and the annular groove (46) of the valve body (43) of the oil pump (1)
Connected to the discharge port (1b) of the oil via the oil passage (47), and the oil chamber (45)
The oil passage (7) is connected to the annular groove (46). Flow Control Valve (41)
The back pressure chamber (51) is connected to the annular groove (46) via an oil passage (52) having an orifice (52a), and the back pressure chamber (51) has an oil passage (53) having a relief valve (53). 54) to the bypass passage (55), and when the pressure in the oil chamber (45) rises, the valve body (43) is moved to the back pressure chamber (51) side to bypass the oil in the oil chamber (45). The pressure of the pressure oil that escapes through the passage (55) and is supplied to the control valve (3) and the power cylinder (4) side is kept constant.

(61) is a vehicle speed responsive valve, and the vehicle speed responsive valve (61) is a flow control valve (41)
It is provided in an oil passage (62) connecting the back pressure chamber (51) and the oil tank (2).

Next, the vehicle speed responsive valve will be described with reference to FIGS.

FIG. 2 is a sectional side view of an essential part of a vehicle speed responsive valve and a final counter gear, and FIGS. 3 and 4 are III-I of FIG. 2, respectively.
The II line and the IV-IV line sectional view are shown.

The vehicle speed response valve (61) meshes with the final counter gear (64) of the mission mechanism and rotates in proportion to the vehicle speed (65).
The lower case (66) and upper case (67)
Support rotatably with.

A rotating member (71) coupled to the rotating shaft (65) through a pin (68) and rotating integrally with the rotating shaft (65) at the upper part of the lower case (66).
And a plurality of movable members (72) ... Are incorporated in the rotating member (71) so as to be movable in the radial direction.

A spherical engagement portion (73) is formed at the outer end of the movable member (72), and the coil spring (74) urges the movable member (72) to a radial force.

The rotating member (71) is a rotatable member (7) loosely fitted to the rotating shaft (65).
Cover with 6).

The rotatable member (76) has an upper surface (78) on which a pin (77) is erected.
And a cylindrical portion (79) vertically extending from the upper surface portion (78) and facing the engaging portion (73) of the movable members (72).

The upper case (67) is formed with a long groove (81) which allows the pin (77) to be guided freely, and is engaged with the pin (77) to form a piston body.
Install (82) in the upper case (67) so that it can move axially.

The upper case (67) is formed with an oil passage (83) that connects the oil passage (62a) on the back pressure chamber (51) side and the oil passage (62b) on the oil tank (2) side. ) And (620b) indicate the ports of the oil passages (62a) and (62b). Then, by moving the steel ball (85) in the axial direction by the shaft portion (82a) of the piston body (82), the port (8) defined by the valve seat (86) is
Adjusting the opening area of 7), the coil spring (92) and the stopper (94) and the steel ball (8) provided between the stopper (91) and the pin (77).
The coil spring (95) interposed between the steel ball (8)
5) is brought into close contact with the valve seat (86) and urged so as to close the oil passage (83).

The elastic force of the springs (74), (92), (95) is the rotating member (71).
Above a predetermined rotation speed of the movable member (72) engaging portion (7
The rotating member (76) is configured to rotate against the elastic force of the spring (95) by the frictional force due to the action of the centrifugal force between the cylindrical member (79) and the cylindrical portion (79).

Since the present embodiment is configured as described above, the rotating member (71) rotates in proportion to the vehicle speed via the final counter gear (64) and the rotating shaft (65), and at a predetermined rotating speed or higher, the rotating speed becomes Move the steel ball (85) accordingly and open the port (87)
(62a), (83), (62b) are connected. Then, the oil in the back pressure chamber (51) is allowed to escape through the oil passages (62a), (83), (62b), the pressure of the pressure oil in the back pressure chamber (51) is reduced, and the valve body (43) is back pressured. The pressure oil supplied to the control valve (3) and the power cylinder (4) side is allowed to escape through the bypass passage (55) by moving to the chamber (51) side, and the steering at high speed is made heavy.

In the above, since the rotating member (71) rotates in proportion to the counter gear (64), that is, in proportion to the vehicle speed, the movable member (72)
The centrifugal force acting on the vehicle accurately corresponds to the vehicle speed. Therefore, the oil passage (83) can be opened and closed with a simple structure so as to correspond to the vehicle speed.

Further, as in the embodiment, when the elastic force of the spring (74) is applied to the movable member (72), the spring constant of the spring (74) is appropriately determined, so that the port corresponding to a wide range of vehicle speed can be obtained. It is also possible to variably adjust the opening area of (87).

Next, a second embodiment will be described with reference to FIG.

The same members as those of the first embodiment and the same parts will be denoted by the same reference numerals. The long groove (1) for guiding the pin (77) to the upper case (67) will be described.
01) is formed and the upper case (67) is axially movable.
(102) is assembled, the pin (77) is engaged with the long groove (103) of the shaft (102), the stopper (105), the stepped portion (106) of the upper case (67), the spring bearing (107), ( 108), stopper (111), coil spring (11
Bias the shaft (102) to the neutral position via 2).

A V-shaped concave groove (113) is formed in the middle of the shaft (102), and the concave groove (113) is made to face the upper case from a direction orthogonal to the shaft (102).
Oil passages (115) and (116) are formed in (67), and the oil passages (115) and (116) are closed by stopper plugs (117) and (118), respectively.

The oil passage (121) connected to the port (620a) is the oil passage (116).
In addition, the oil passage (122) connected to the port (620b) is the oil passage (122).
Connect to (115) respectively.

A coil spring (124) is attached to each of the oil passages (115) and (116).
The small-diameter steel balls (125), (125) and the large-diameter steel ball (126) are installed by urging the steel ball (126) into close contact with the valve seat (127) and the port (127). 128) so that it is closed.

Thus, when moving forward or backward, when the rotating member (71) rotates at a predetermined rotation speed or more, the shaft (102) moves axially via the pin (77), and the concave groove (113) moves, Small diameter steel balls (125),
The large diameter steel ball (126) is moved to the outside of the shaft (102) via the (125) to open the ports (128) and (128), and the back pressure is applied at a predetermined vehicle speed or higher when moving forward or backward. The oil in the room (51) is released to make the steering heavy.

In the embodiment, the case where the present invention is applied to the on-off valve that opens and closes the oil passage has been described, but it goes without saying that the present invention is not limited to this and can be applied to various control valves such as a directional control valve. is there.

(Effects of the Invention) As is apparent from the above description, according to the present invention, the pressure adjusting valve body for high load control provided in the back pressure circuit of the flow control valve is provided with a separate pressure source for operation. Since it is operated reliably in accordance with the vehicle speed without the need, the power steering device capable of controlling the supplied hydraulic pressure in accordance with the vehicle speed can be configured with a simple structure.

[Brief description of drawings]

FIG. 1 is a hydraulic circuit diagram of a power steering device, FIG. 2 is a side sectional view of a vehicle speed responsive valve and a final counter gear, and FIGS. 3 and 4 are III-III lines of FIG. 2, respectively.
FIG. 5 is a sectional view taken along the line IV-IV and FIG. 5 is a sectional view of the essential parts of the second embodiment. In the drawing, (1) is an oil pump, (3) is a control valve, (4) is a power cylinder, (41) is a flow control valve, (62a) is a back pressure circuit, (65) is a rotary shaft, and (66) ) Is a lower case, (67) is an upper case, (71) is a rotating member, (72) is a movable member, (76) is a rotated member, (77) is a pin, (82) is a piston body, (85) Is a steel ball (pressure control valve body), and (92) and (95) are springs.

Claims (3)

[Scope of utility model registration request] 1. A vehicle speed responsive valve for adjusting the supplied hydraulic pressure by being provided in a back pressure circuit of a flow control valve for controlling the supplied hydraulic pressure for power steering assist, the vehicle speed being connected to a power transmission system. A rotating member that rotates at a rotating speed corresponding to the above, a movable member that is installed in the rotating member so as to be movable in a substantially radial direction of the rotating member, and a frictional force between the movable member and the movable member increases the vehicle speed. A rotatable member that receives a corresponding rotating torque; a pressure adjusting valve body that engages with the rotating member and opens and closes the back pressure circuit by the rotating torque of the rotating member; And a vehicle speed responsive valve comprising an elastic means for regulating its operating pressure. 2. The vehicle speed responsive valve according to claim 1, wherein the movable member is urged by a spring in the radial direction of the rotating member. 3. The vehicle speed responsive valve according to claim 1, wherein the valve element operates in association with forward and reverse rotations of a rotated member.