JPS61139562A - Fluid control unit in hydraulic steering device - Google Patents

Abstract

PURPOSE:To facilitate the assembly and disassembly of a fluid control unit, by enabling an electromagnetic flow rate control valve controlled in accordance with the speed of a vehicle, etc. to be directly incorporated in a valve hole in a pump body, and by incorporating a fixed restrictor orifice memter in a valve hole. CONSTITUTION:In an arrangement in which hydraulic pressure from a pump device 50 including an engine drive vane type pressure generating means 51 is fed to a reaction mechanism (not shown) is a power steering device, the pump body 52 of the pump device 50 are formed therein with valve first and second valve holes 53, 54 into which flow regulating spools 55, 56 are slidably fitted, respectively. A bypass passage 79 communicated to the suction side of the pump device 20 is connected to the second valve hole 54, and is opened and closed by the above-mentioned spool 56 which is urged by a spring 66. Further, hydraulic oil between a fixed oirifice 71a and a control section 72 whose opening area is changed in association with the operation of a solenoid valve 67 secured to an opening section on the front chamber 63 side defined by the spool 56, is led to the reaction mechanism.

Description

[Detailed Description of the Invention] <Industrial Application Field> The present invention provides a power steering system equipped with a reaction force mechanism that generates a steering reaction force according to vehicle speed, etc. The present invention relates to a fluid control device that controls a fluid control system.

<Prior Art> A power steering device equipped with a reaction force mechanism is known, and a pressure generating means of a pump device is used as a fluid control device that controls pressure oil supplied to the reaction force mechanism according to vehicle speed, etc. a first flow control valve that controls the pressure oil generated from the flow rate to a predetermined flow rate required for the power steering device and bypasses excess flow to a bypass passage;
a second flow rate control valve that controls the bypass flow rate bypassed by the first flow rate control valve to a constant flow rate and bypasses the surplus flow to the low pressure side; The oil is controlled to a control pressure according to the vehicle speed, etc.
A device has been devised that is composed of an electromagnetic pressure control valve that performs i+ control, and means for introducing the control pressure controlled by the electromagnetic pressure control valve into the reaction force mechanism.

<Problems to be Solved by the Invention> The first flow control valve and the second flow control valve are provided in a pump body of a pump device, and a pressure difference is generated in the pump body before and after the second flow control valve. A block is fixed to this pipe, and the electromagnetic pressure control valve is installed in the middle of a pipe connecting the pump device and the reaction force mechanism of the power steering device. The problem is that the number of parts increases and the ease of assembly deteriorates. Further, the fixed throttle member is smaller than the hole diameter of the valve hole that slidably guides the second flow control valve, and must be attached to the valve hole via an adapter, which poses a problem of increasing the number of parts. Furthermore, there is the problem that the fixed throttle member and electromagnetic pressure control valve cannot be replaced at the same time.

Means for Solving the Problems> The present invention was made to solve the above problems, and includes a valve hole through which pressure oil is introduced into the pump body of a pump device, and a valve hole communicating with the valve hole on the tank side. A flow rate adjustment spool for adjusting the opening degree of the bypass passage is slidably inserted into the valve hole, and the flow rate adjustment spool divides the inside of the valve hole into a front chamber and a rear chamber. After that, a spring is inserted in the chamber to press the flow rate adjustment spool in the direction of closing the bypass passage, and a solenoid valve to which a current is applied according to the vehicle speed or the like is fixed to the opening on the front chamber side.
A flow path is formed in the valve body of this solenoid valve, one side communicating with the valve hole and the other side communicating with the low pressure side, a fixed throttle member is provided on the upstream side of this flow path, and the opening area of the solenoid valve is formed on the downstream side. Alternatively, a control section that can change the opening pressure is provided, and an introduction hole for introducing pressure oil into the reaction force mechanism and the rear chamber is formed between the fixed throttle member of the valve body and the control section.

<Example> Embodiments of the present invention will be described below based on the drawings.

In FIG. 2, reference numeral 10 denotes a gear housing forming the main body of the power steering device, and a pinion shaft (output shaft) 11 is rotatably supported in this gear housing 10, and this pinion shaft 11 is rotated in a direction crossing this. Rack shaft 1 that can be slid on
It is meshed with 4.

Both ends of the rack shaft 14 are connected to steering wheels via a required steering link mechanism, and a piston of a power cylinder (not shown) is operatively connected to the rack shaft 14.

A valve housing 18 is fixed to the gear housing 10, and a rotary servo valve 20 is disposed within the valve housing 18.
is stored. The rotary type servo valve 20 is composed of a sleeve valve member 21 and a rotor valve member 22, which are relatively rotatable about the axis of the pinion shaft 11. (shaft) 24. Steering shaft 24
is flexibly connected to the pinion shaft 11 via a torsion bar 25, and is also engaged via an engaging portion 43 so as to be relatively rotatable by a predetermined amount.

A plurality of boat grooves 21a and 22a are formed on the inner periphery of the sleeve valve member 21 and the outer periphery of the rotor valve member 22 at equal angular intervals on the circumference. , the supply boat 26 is connected to one of the supply and discharge boats 28 and 29 connected to the compartment of the power cylinder, and the other is connected to the discharge boat 27.

The valve housing 18 is attached to one end of the pinion shaft 11.
A cylindrical portion 30 that rotatably fits inside is formed, and one end of this cylindrical portion 30 is connected to the sleeve valve member 21 via a connecting pin 31. A reaction force cylinder chamber 33 is formed in the cylindrical portion 30 concentrically with the pinion shaft 11, and a flange-shaped reaction force receiving portion 34 formed on the steering shaft 24 can be relatively rotated in this reaction force cylinder chamber 33. It is fitted.

A ring-shaped reaction force piston 35 is fitted into the reaction cylinder chamber 33 so as to be able to slide in the axial direction, facing the reaction force receiving portion 34 . It is prevented from rotating. The inner periphery of the reaction force piston 35 is fitted onto the steering shaft 24, and the reaction force piston 35 divides the reaction force shilling chamber 33 into a left chamber and a right chamber. The left ventricle is connected to an introduction port 40 into which reaction oil pressure is introduced, as will be described later, and the right ventricle is connected to a drain port 41 connected to a reservoir.

A plurality of conical recesses 34a, 35a are formed on the circumference of the opposing surfaces of the reaction force receiving part 34 and the reaction force piston 35, and a plurality of engagement balls are formed on the circumference that engage with these recesses 34a, 35a. 36 is interposed between the reaction force receiving portion 34 and the reaction force piston 35. Therefore, the reaction force piston 35 has a web washer 39 provided on its back side.
is constantly pressed in the direction of engagement with the engagement ball 36. The reaction force silling chamber 33, reaction force receiving part 34,
A reaction force mechanism 42 is constituted by the reaction force piston 35 and the engagement ball 36.

Next, a fluid control device that controls the pressure oil supplied to the reaction force mechanism 42 will be explained.

In FIG. 1, reference numeral 750 indicates a pump device, and the pump device 50 is provided with a vane-type pressure generating means 51 that is driven by an automobile engine and generates pressure oil.

Reference numeral 52 indicates a pump body of the pump device 50, and the pump body 52 has a first valve hole 53 and a second valve hole 54 formed in parallel with the first valve hole 53. First valve hole 5
3, a first flow rate adjustment spool 55 is slidably inserted into the second valve hole 54, and a second flow rate adjustment spool 55 is slidably inserted into the second valve hole 54.
6 is slidably inserted. The interior of the first valve hole 53 is divided by the spool 55 into a front chamber 57a and a rear chamber 57b, and a spring 58 that presses the spool 55 is inserted in the rear chamber 57b. A union 59 is attached to the opening on the side of the front chamber 57a, and a fixed throttle 60 is formed in the union 59. The fluid after the fixed throttle 60 is the second
It is supplied to the supply port 26 shown in the figure and guided to the rear chamber 57'b through the introduction passage 61. The pressure of the fluid before and after the fixed throttle 60 acts on the front and back of the spool 55, and the spool 55 slides according to this pressure difference, and the spool 55 forms a hole in the pump body 52 at right angles to the first valve hole 53. The opening degree of the bypass passage 62 is adjusted. This bypass passage 62 communicates with the second valve hole 54 .

A front chamber 63 is formed inside the second valve hole 54 by the spool 56.
and a rear chamber 64, and a spring 66 is interposed between a stopper 65 provided in the rear chamber 64 and the spool 56. A valve body 68 of an electromagnetic flow control valve 67 is screwed into the opening on the front chamber 63 side, and a throttle member 6 is attached to this valve body 68.
9 are integrally connected. A flow path 70 communicating with the second valve hole 54 is formed in the throttle member 69, and the flow path 70 communicates with the second valve hole 54.
A fixed aperture member 7 with a fixed aperture 71a formed on the upstream side of the
1 is provided, and a variable throttle 72 is formed on the downstream side of the flow path 70. This variable aperture (control section) 72 is connected to the rod 7
The aperture area of the diaphragm is changed by advancing and retracting the rod 73, and the rod 73 is integrally connected to a spool 75 that is attracted to the yoke 74 side by a current applied to a solenoid 80. The fluid after the variable throttle 72 passes through a discharge passage 76 formed in the valve body 68 and is returned to the suction side of the pump device 50. Valve body 68 and throttle member 6
9 is formed with an introduction hole 77 that communicates with the flow path 70 between the fixed throttle member 71 and the variable throttle member 72, and the fluid after the introduction hole 77 is guided to the introduction port 40 shown in FIG. It is led to the rear chamber 64 through an introduction passage 78 formed therein. The pressure of the fluid before and after the fixed throttle 71a acts on the front and back of the spool 56, and the spool 56 slides according to this pressure difference, and the spool 56 forms a hole in the pump body 52 at right angles to the second valve hole 54. The opening degree of the bypass passage 79 is adjusted. This bypass passage 79
is connected to the suction side of the pump device 50.

In the embodiment described above, the electromagnetic flow control valve 67 is directly attached to the opening of the second valve hole 54 of the pump body 52, so the number of parts can be reduced and assembly is easy. Further, the fixed throttle member 71 is connected to the pump body 52 via the valve body 68.
The number of parts can be reduced because the valve body 68 is attached to the pump body 52, and the fixed throttle member 71 and the electromagnetic flow control valve 67 can be replaced at the same time by simply removing the valve body 68 from the pump body 52.

Next, the operation will be explained based on the above-described configuration. The pressure oil from the pressure generating means 51 is guided to the first valve hole 53, and the spool 55 is slid according to the pressure difference before and after the fixed throttle 60, and the opening degree of the bypass passage 62 is adjusted to open the supply port. 26 is controlled to a constant flow rate, and excess flow is bypassed to the bypass passage 62. This piped oil is guided to the second valve hole 54, and the fixed throttle 71a
By sliding the spool 56 according to the pressure difference before and after and adjusting the opening degree of the bypass passage 79, the amount of oil guided to the passage 70 is controlled to a constant flow rate, and the excess flow is bypassed to the bypass passage 79. do.

By applying a current according to the vehicle speed etc. to the solenoid 80 and drawing the spool 75 to the yoke 74 side, the spool 7
A rod 73 integrally connected to 5 moves forward and backward. rod 73
As the variable throttle 72 advances and retreats, the throttle area of the variable throttle 72 changes, and the oil pressure in front of the variable throttle 72 changes. variable aperture 72
The oil pressure, which is controlled by controlling the constriction area, is guided to the reaction cylinder chamber 33 through the introduction hole 77 and the introduction port 40, and the control pressure acts on the reaction force piston 35.

The oil pressure acting on the reaction force piston 35 is transferred to the engagement ball 36.
By pressing the steering shaft 2 against the reaction force receiving part 34 through
4 and the pinion shaft 11 becomes difficult to occur, and the handle torque changes. The oil guided to the bypass passage 79 and the discharge passage 76 is returned to the suction side of the pump device 50.

The present invention is an electromagnetic flow control valve 6 as shown in Fig. 1 as a solenoid valve.
7, an electromagnetic relief valve 9 as shown in FIG.
0 may be attached to the pump body 91. In this device, a flow path 95 communicating with a valve hole 94 is formed in a throttle member 93 integrally connected to a valve body 92, a fixed throttle member 96 is provided on the upstream side of this flow path 95, and a fixed throttle member 96 is provided on the downstream side of the flow path 95. A control section 98 that is opened and closed by a ball valve 97 is provided. An introduction hole 99 is formed in the valve body 92 and the control member 93 between the fixed throttle member 96 and the throttle part 98 and communicates with the flow path 95, so that the oil after the introduction hole 99 is guided to the reaction force mechanism and the rear chamber 100. It has become. The oil after the control section 98 is returned to the suction side of the pump device. Solenoid 10
The spool 102 is attracted toward the yoke 1°3 depending on the magnitude of the current applied to the ball valve 97, and the pressing force of the spring 104 that presses the ball valve 97 is changed. Fixed aperture member 9
When the pressure of the oil after the fixed throttle member 96 exceeds the pressure set in the spring 104, it is released via the control section 98, and the pressure of the oil after the fixed throttle member 96 is controlled to a predetermined pressure.

<Effects of the Invention> As described above, the present invention allows the electric regulating valve to be attached directly to the pump body, which has the advantage of facilitating assembly and eliminating the need for extra parts. Also, since the fixed throttle member is attached to the pump body via the valve body, no extra parts are required to attach the fixed throttle member to the pump body, and the solenoid valve and fixed throttle member can be attached by removing the valve body. Since they can be replaced at the same time, there is an advantage that replacement is easy.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of a fluid control device showing an example of an embodiment of the present invention, FIG. 2 is a sectional view of a power steering device, and FIG. 3 is a sectional view of a fluid control device showing another embodiment. 42...-reaction force mechanism, 52.91... pump body, 5
'4.94...Second valve hole, 56...Spool, 6
3... Front chamber, 64. 100... Rear chamber, 66... Spring, 67... Solenoid flow control valve, 68. ,'92
...-valve body, 69. ．． 93... Aperture member, 7.0
．． 95...□Flow path, 71°96...Fixed throttle member,
71a...Fixed aperture, 72...Variable aperture (control unit)
, 77.99...Introduction hole, 79...Bypass passage,
90...Electromagnetic relief valve, 97...Ball valve, 98
...control section.

Claims (1)

[Claims] (1) In a power steering device equipped with a reaction force mechanism that generates a steering reaction force according to vehicle speed, etc., a fluid control device that controls pressure oil from a pump device to a pressure that is supplied to the reaction force mechanism. , a valve hole through which pressure oil is guided to the pump body of the pump device, a bypass passage communicating with the valve hole and guided to the tank side, and a flow rate adjustment spool for adjusting the opening degree of the bypass passage in the valve hole. The flow rate adjustment spool is slidably inserted into the valve hole to divide the inside of the valve hole into a front chamber and a rear chamber, and a spring is inserted in the rear chamber to press the flow rate adjustment spool in a direction to close the bypass passage. A solenoid valve to which a current is applied according to vehicle speed, etc. is fixed to the opening on the front chamber side, and a flow path is formed in the valve body of the solenoid valve, one side communicating with the valve hole and the other side communicating with the low pressure side. A fixed throttle member is provided on the upstream side of this flow path, and a control section is provided on the downstream side where the opening area or opening pressure can be changed by the electromagnetic valve, and the reaction force is generated between the fixed throttle member of the valve body and the control section. 1. A fluid control device for a power steering device, characterized in that an introduction hole is formed for introducing pressure oil into a mechanism and the rear chamber.