JPH0427666A - Flow rate control device - Google Patents

Abstract

PURPOSE:To reduce the size of a flow rate control device by forming a connector mounting hole, having a throttle passage, adjacently to and axially externally of a valve containing hole with which a spool valve to control an amount of pressure oil returned to the suction side of a pump through regulation of the opening of a bypass passage is engaged. CONSTITUTION:A flow rate control device A to regulate a flow rate of pressure oil, with which a pump device used for a power steering device is provided, is provided with a connector mounting hole 2, a valve containing hole 3, a feed passage 4 communicated to the connector mounting hole 2 through the valve containing hole and a first communicating passage P1, and a bypass passage 5 through which the suction side of the pump device is communicated to the containing hole 3, which are all formed in a housing 1 of the pump device. A connector 6 coupled on the power steering device side is joined in a screwed-in manner with the connector mounting hole 2, and a spool valve 7 to regulate the opening of the bypass passage 5 is slidably engaged with the containing hole 3. The connector mounting hole 2 is formed adjacently to and radially externally of the valve containing hole 3, whereby an overall length is decreased compared with a case in which the two holes are arranged in series.

Description

[Detailed Description of the Invention] <Industrial Application Field> This invention sends pressure oil discharged from a pump to a power steering device, and directs excess pressure oil to the pump suction side via a bypass passage. This invention relates to a return flow rate control device.

<Prior Art> In recent years, most automobiles have come to be equipped with a power steering device (power steering) that uses hydraulic pressure to assist the steering force.

The pump device used in this power steering device is equipped with a flow rate control device that adjusts the flow rate of pressure oil to the power steering device side.

This flow control device returns most of the pressure oil discharged from the pump to the suction side of the pump via the bypass passage in response to the increase in pump rotation speed as the vehicle speed increases. , functions to maintain the flow rate to the power steering device side at a predetermined level.

Furthermore, the above-mentioned flow control device reduces the flow rate to the power steering device when the pump rotation speed increases above a predetermined value, thereby increasing the steering force when driving at high speeds and ensuring safety. (For example,
5-712.5).

However, this flow control device adjusts the flow rate to the power steering device by increasing or decreasing the opening degree of the bypass passage based on the displacement of the spool valve. When high pressure is generated on the steering gear side, this high pressure moves the spool valve to restrict the bypass flow, which restores the lowered flow to the power steering gear side during high-speed running. , there was a problem in that the operating force of the steering became light.

Therefore, by variably controlling the flow rate in accordance with the increase in pump rotation speed, regardless of the displacement of the spool valve,
A non-return type flow rate control device has been provided which prevents the lowered flow rate from returning (see Japanese Patent Publication No. 37749/1983).

As shown in FIG. 5, this flow rate control device includes a restriction passage 103 that provides limited communication between a pressure oil supply passage 100 from a pump and a valve housing hole 102 in which a spool valve 101 is housed.
, a control valve 106 that varies the restriction of a restriction passage 105 to the power steering device side 109 provided in the connector 104, and a bypass passage 108. In this flow rate control device, when the pump rotation speed increases, the restriction passage 1
03 increases the flow path resistance against the increase in flow rate due to the increase in the pump rotation speed, thereby increasing the supply path 100.
The control valve 106 restricts the flow rate by restricting the throttle passage 105 in response to the increase in the pressure difference between the valve storage hole 103 and the valve storage hole 103.

<Problem to be solved by the invention> However, in the above flow control device, the connector 1
Connector mounting hole 107 for attaching 04 and spool valve 1
Since the valve housing hole 102 that accommodates the valve housing 01 is arranged concentrically and in series with each other, the overall length of the device becomes long, making it difficult to miniaturize the device. For this reason, there was a problem in that the above-mentioned flow rate control device could not be built into small-capacity pumps installed in light vehicles due to space limitations.In addition, since the placement position of the connector 104 was restricted,
There was no flexibility in piping, making it even more difficult to install the device.

The present invention has been made in view of the above problems, and an object of the present invention is to provide a flow control device that allows the arrangement position of a connector to be arbitrarily selected and that can achieve miniaturization.

<Means for Solving the Problems> In order to solve the above problems, the flow rate control device of the present invention has the following features:
A connector mounting hole provided in the housing, a connector installed in the connector mounting hole, and a supply passage that supplies pressurized oil discharged by the pump to the power steering device through a throttle passage provided in the connector. and a valve housing hole provided in the housing, a bypass passage that communicates the valve housing hole and the pump suction side and returns excess pressure oil to the pump suction side, and a valve housing hole that is slidably fitted into the valve housing hole. By adjusting the opening degree of the bypass passage, the spool valve, which controls the amount of pressure oil returned to the pump suction side, communicates with the supply passage and the valve storage hole in a limited manner, thereby reducing the flow rate due to an increase in the pump rotation speed. A restriction passage is provided in the connector to generate a differential pressure between the supply passage and the valve housing hole in response to an increase in the pressure difference between the supply passage and the valve housing hole, and a restriction passage is provided in the connector to generate a pressure difference between the supply passage and the valve housing hole in response to an increase in the pressure difference between the supply passage and the valve housing hole. The flow rate control device includes a throttle control valve, and the connector mounting hole is arranged radially outward and adjacent to the valve housing hole.

<Function> According to the flow control device having the above configuration, the connector mounting hole is adjacent to the valve mounting hole in the radial direction outward, so the overall length can be made shorter than when both are arranged in series. I can do it. Further, since the connector mounting hole can be arranged in any direction with respect to the valve housing hole, flexibility in connecting piping to the connector can be ensured.

<Example> Embodiments will be described below based on the accompanying drawings showing examples.

FIG. 3 is a sectional view showing a pump device incorporating the flow rate control device A of the present invention. The pump device includes a rotor 1 which is rotatably driven by an automobile engine via a drive shaft 10 in a housing 1 made of aluminum alloy.
1. Cam ring 1 that generates pressure oil between it and rotor 11
2. It is equipped with an end plate 14 and a pressure plate 15, etc., which sandwich the rotor 11 and cam ring 12 to form a pump chamber 13, and the pressure oil discharged by the pump device is controlled in flow rate through a supply passage 4, which will be described later. It is supplied to the device A, and is sent to the power steering device through the flow control device A.

FIG. 1 is a sectional view showing details of the flow rate control device A. This flow rate control device A includes a housing 1 of a pump device.
Connector mounting hole 2 and valve storage 6 3 are drilled in each
, a first communication path P1 and a second communication path P2 that communicate the connector mounting hole 2 and the valve housing 63, and communicate with the discharge side of the pump device through the valve housing hole 3 and the first communication path P1. a supply passage 4 that communicates with the connector mounting hole 2; a third communication passage P3 that communicates the connector mounting hole 2 and the supply passage 4; and a bypass passage 5 that communicates the suction side of the pump device with the valve storage hole 3. It is equipped with

A connector 6 connected to the power steering device side is screwed into the connector mounting hole 2, and a bypass passage 5 is screwed into the valve housing 63.
A spool valve 7 for adjusting the opening degree is slidably fitted. Further, the supply passage 4 and the valve housing hole 3 are partitioned by a partition wall 16 that is integral with the housing 1, and a restriction passage 9 is bored in the partition wall 16.

The connector 6 includes a union 61 with a communication hole 62 formed therein, one end 6 of the union 61, a sleeve 63 fitted inside the union 61, a ring-shaped sleeve 63 fitted into the middle part 62a of the communication hole 62, and forming a throttle passage 65. The aperture member 64, the sleeve 63
is slidably fitted in the axial direction so that the throttle passage 65 can be closed, and a throttle passage 67 is provided at the tip of the center hole 66a.
A compression coil spring 68 is provided between the throttle member 64 and the rod spool 66 and biases the rod spool 66 in the direction of opening the throttle passage 65. There is.

One end 62b of the communication hole 62 of the union 61 is formed with a threaded portion 62c for connection to a servo valve device (not shown) of a power steering device. Outer groove 6 of union 61
An O-ring 69 provided at 1b seals between the outer periphery of the union 61 and the housing 1. An annular passage 24 is provided on the outer periphery of the union 61 near the O-ring 69 and is connected to the power steering device side through a communication hole 25. The valve storage hole 3 is in communication with a second valve chamber 32, which will be described later, through a communication path P2 of the valve storage hole 3.

A plurality of communication holes 66b are formed on the front end side of the rod spool 66 to communicate the center hole 66a between the throttle member 64 and the front end side. Further, the center hole 66a of the rod spool 66 is communicated with a first valve chamber 31, which will be described later, of the valve housing 63 via the first communication path P1. The pressure within the first valve chamber 31 is applied between the valve member 64 and the member 64 .

On the other hand, the sleeve 63 is formed with a pressure introduction hole 63a that communicates the annular gap 20 between the inner surface of the sleeve 63 and the back surface of the rod spool 66 with the supply passage 4 via the third communication passage P3. As a result, the pressure inside the supply passage 4 is applied to the rear side of the rod spool 66.

Therefore, the rod spool 66 is loaded with the differential pressure between the supply passage 4 and the first valve chamber 31, and due to the increase in this differential pressure, the rod spool 66 is loaded with the pressure difference as shown in FIG. The throttle passage 6 resists the compression coil spring 68.
5 side and closes the throttle passage 65.

A sealing member 8 with an O-ring is fitted into one end 3a of the valve housing 63 to seal the one end 3a, and the sealing member 8 is fixed by a circlip 81.

Further, the spool valve 7 has a comb shape, and a first valve chamber 31 and a second valve chamber 32 are formed on both sides of the spool valve 7.

The first valve chamber 31 is communicated with the supply passage 4 via the restriction passage 9 . Further, a spool valve 7 is provided in the second valve chamber 32.
a compression coil spring 33 that presses the valve toward the first valve chamber 31;
is provided, and by this compression coil spring 33,
Normally, the spool valve 7 is arranged at a position that blocks communication between the supply passage 4 and the bypass passage 5. However, the movement of the spool valve 7 in the direction of the supply passage 4 is regulated by a stopper 34 provided in the valve housing hole 3 in order to maintain the supply passage 4 and the first valve chamber 31 in a state of communication at all times. There is.

According to this embodiment, the pressure oil sent from the pump device is transferred from the supply passage 4 to the first valve chamber 3 through the restriction passage 9.
1, and from this first valve chamber 31, a first communication path P
1. Center hole 66a1 of rod spool 66, communication hole 66b
1, throttle passage 67, throttle passage 65, and communication hole 62
It is sent to the power steering device side via the.

Since the pump discharge flow rate is low when the pump rotation speed is low, the spool valve 7 closes the bypass passage 5, and the entire pump discharge flow rate is sent to the power steering device side via the throttle passage 65, 67. .

Then, as the pump rotation speed increases and the discharge flow rate increases, the spool valve 7 is slid toward the second valve chamber 32 side to balance the pressure difference before and after the throttle passage 65, 67, and the bypass The passage 5 is opened and the surplus flow is returned to the pump suction side via the bypass passage 5 (see Figure 2).
. Thereby, the flow rate of the pressure oil sent to the power steering device side is maintained at a predetermined amount determined by the throttle passage 65 and the throttle passage 67.

When the pump rotation speed further increases and the discharge flow rate increases as the automobile shifts to high-speed driving, a pressure difference is created between the supply passage 4 and the first valve chamber 31 due to the passage resistance of the restriction passage 9. is generated, but this pressure is caused by the third communication path P3,
A load is applied to the back side of the rod spool 66 through the pressure introduction hole 63a1 and the annular passage 20, and this pressure causes
The rod spool 66 resists the compression coil spring 68,
It is moved to the throttle passage 65 side and closes the throttle passage 65 (see FIG. 2). Thereby, the flow rate of the pressure oil sent to the power steering device side is reduced to a predetermined amount determined only by the throttle passage 67.

Therefore, when the vehicle is running at high speed, the steering assistance force provided by the power steering device can be reduced to increase the steering operation force, and the stability of the vehicle when running at high speed is ensured.

Closing of the throttle passage 65 by the rod spool 66 is
The supply passage 4 caused by the flow resistance of the restriction passage 9
This is done based on the pressure difference between the spool valve 7 and the first valve chamber 31, and is not based on the displacement of the spool valve 7 as in the conventional case. Therefore, even if the power steering device is activated during high-speed running and the spool valve 7 is moved by the pressure corresponding to the steering resistance, the throttle passage 65 is reliably closed by the rod spool 66, so the power Regardless of an increase in the load pressure of the steering device, the flow rate drop characteristic can be maintained unchanged.

In the above embodiment, since the connector mounting hole 2 and the valve storage hole 3 are arranged in parallel, the overall length can be shortened compared to a conventional flow control device in which these are arranged in series. As a result, the device can be made smaller.

FIG. 4 is a sectional view showing another embodiment. This embodiment differs from the previous embodiment in that the rod spool 66 is directly slidably fitted into the connector mounting hole 2.

According to this embodiment, since the sleeve 63 is not necessary,
This has the advantage that assembly man-hours and costs can be reduced accordingly.

In addition, when the connector mounting hole 2 and the valve storage hole 3 are arranged in parallel as in the above embodiment, the connector mounting hole 2
In some cases, the respective axes of the valve storage hole 3 and the valve housing hole 3 are arranged so as to intersect with each other. In this case, the direction of the connector 6 can be set to a desired direction by appropriately selecting the above-mentioned crossing angle. . In short, connector mounting hole 2
It is only necessary that the valve housing 3 and the valve housing 3 are disposed adjacent to each other radially outward.

<Effects of the Invention> As described above, according to the flow rate control device of the present invention, since the connector mounting hole is adjacent to the valve mounting hole in the radial direction outward, compared to the case where both are arranged in series, As a result, the overall length can be shortened, and the device can be made smaller.

Further, since the connector mounting hole can be arranged in any direction with respect to the valve housing hole, flexibility in connecting piping to the connector can be ensured.

Therefore, the device can be installed even in light vehicles, etc., which do not have a large installation space, and this has the unique effect of further popularizing the device.

[Brief explanation of the drawing]

Fig. 1 is a sectional view showing a flow rate control device as an embodiment of the present invention, Fig. 2 is a sectional view showing the operation of a spool valve and rod spool, and Fig. 3 is a pump incorporating the flow rate control device of this invention. FIG. 4 is a sectional view showing another embodiment, and FIG. 5 is a sectional view showing a conventional example. 2...Connector mounting hole, 3...Valve storage hole, 4...
Supply passage, 5...Bypass passage, 6...Connector, 7
... Spool valve, 9... Restriction passage, 66... Rod spool (control valve).

Claims (1)

[Claims] 1. Supplying pressurized oil discharged by a connector mounting hole provided in the housing, a connector mounted to this connector mounting hole, and a pump to the power steering device through a throttle passage provided in the connector. A supply passage, a valve storage hole provided in the housing, a bypass passage that communicates the valve storage hole with the pump suction side and returns excess pressure oil to the pump suction side, and a valve storage hole that is slidably inserted into the valve storage hole. By adjusting the opening degree of the bypass passage, the spool valve, which controls the amount of pressure oil returned to the pump suction side, has limited communication with the supply passage and the valve storage hole, and the increase in pump rotation speed A restriction passage that generates a differential pressure between the supply passage and the valve housing hole in response to an increase in the flow rate; What is claimed is: 1. A flow control device comprising a control valve that throttles a passage, wherein the connector mounting hole is adjacent to the valve housing hole on the outside in a radial direction.