JPS61122070A - All hydraulic type power steering apparatus - Google Patents

Abstract

PURPOSE:To balance the hydraulic thrust acting on the valve cutting surface of a valve body by equalizing the area of pressure surface generating the hydraulic thrust due to the high pressure of a pump side every valve body. CONSTITUTION:A steering wheel is operated, and when an input shaft 20 is rotated, the first valve body 36 is turned at the same time of the input shaft. On the other hand, since the second valve body 39 is turned through a resilient transmission member consisting of leaf springs which are interposed between the cylindrical portion 20C of the input shaft and a sleeve 90, given phase difference between the first valve body 36 and the second valve body is generated. At the same time, a pump driving shaft 3A is eccentrically rotated through the sleeve 90, and a metering pump 3 is operated to supply oil to the left oil chamber or the right oil chamber of a power cylinder. However, since a difference portions 200, 201 in diameter, a hydraulic pocket 204 and the annular surface 203 of outer periphery edge in a valve switching surface are provided in each valve body, the hydraulic pressure acting on a valve switching surface direction is equalized to the hydraulic pressure on a reverse direction, and thus only the force due to pressing means 94 acts on the valve switching surfaces, and the operating performance of the steering wheel is improved.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to a fully hydraulic power steering system (hereinafter referred to as HPS) suitable for vehicles such as forks, wheel rotors, and tractors, and particularly relates to a fully hydraulic power steering system (hereinafter referred to as HPS) suitable for vehicles such as forks, wheel rotors, and tractors. The present invention relates to a fully hydraulic power steering device that requires less power.

[Conventional technology]

In the conventional HPS, as shown in FIG. 10, the switching pulp 2 is switched depending on the steering direction of the wheel/rubber 6 to supply pressure oil sent from the external pump 1 to the metering pump 3.
Pressure oil in an amount equal to the steering amount is discharged from the metering pump 3, and is supplied to, for example, one hydraulic chamber 4A of the power cylinder 4 switched by the switching pulp, while the other hydraulic chamber 4B The oil is returned to the tank 5 via the switching pulp 2, and the piston rod of the power cylinder is actuated either left or right to obtain the output necessary for steering the wheels.

As an example of HPS for this food, Japanese Patent Application Laid-Open No. 49-94028
The switching pulp section of the HPS has a plurality of annular oil passages and ports formed on the inner circumferential surface of the pulp housing, and a plurality of annular oil passages and ports that are in sliding contact with the inner circumferential surface of the pulp housing. It consists of a sleeve in which holes and grooves are formed, and a spool that is slid into contact with the inner surface of the sleeve, has a large number of holes and grooves formed in it, and has a connection part with a handle shaft at one end. The spool is rotated by the operation of the spool to create a rotational angle deviation between the spool and the sleeve, thereby switching the oil passage and switching the direction of pressure oil being delivered to the power cylinder.

[Problem that the invention seeks to solve]

However, in general, in order to make the discharge flow rate of the metering pump equal to the steering angle, it is necessary to Oil spills or inflows shall be prevented. Otherwise, the cylinder stroke (=tire turning angle) will often be too much or too little for the steering angle amount.
It becomes difficult. Furthermore, since a large number of suction and discharge ports are formed on the metering pump side, a large number of holes and grooves must be provided on the valve body side in correspondence with these ports. In this way, in order to prevent oil from flowing out or flowing in from the valve overlapping part, it is necessary to make the allowable tolerance of the valve overlapping part extremely small. Accuracy must be increased, and precise machining is required. Furthermore, since a large number of holes and grooves must be machined with high precision, there is a problem in that work efficiency deteriorates.

For this reason, it is conceivable to use a disc-shaped valve body as the valve body, but it has the disadvantage that hydraulic thrust acts on the disc-shaped valve body μ and the pulp switching surface, which creates frictional resistance and makes the handle heavy. be. In particular, when the inside of the pulp is used as a high-pressure passage, when the pulp is actuated by operating the handle, the pressure on the valve switching surface of the disc-shaped valve element is different when the pressure on the pump side is high. occurs, and the hydraulic thrust of the a7 balance acts on a portion of the valve, resulting in an increase in the frictional force on the valve switching surface, which slows down the pulp operation, resulting in a heavy handle and poor operability.

This invention was made in view of the above circumstances, and it improves processing efficiency by reducing the number of pulp components that require high processing accuracy, and also balances the hydraulic thrust acting on the valve overlapping part to provide valve driving force. That is, the object of the present invention is to provide a fully hydraulic power steering device that reduces steering force.

[Means for solving problems]

A fully hydraulic power steering device ff according to the present invention includes a pulp housing having ports connected to each hydraulic chamber of the power cylinder, an external pump, and a tank on the outer peripheral surface, a bearing in the front part, and an internal pump mounting seat in the rear part. , a metering pump is mounted on the internal pump mounting seat, and a metering pump that converts pressure oil sent from an external pump into an oil volume equal to the steering amount and supplies it to each hydraulic chamber of the power cylinder; and a metering pump that is supported by the bearing and is connected to the handle shaft. an input shaft having a connecting portion; a pump drive mechanism that drives the metering pump in synchronization with rotation of the input shaft; and a first valve switching surface fixed to the input shaft and having a valve switching surface perpendicular to the axis. a second valve body disposed between the first valve body and the metering pump, the second valve body having a valve switching surface that switches an oil path by a cooperative action with the first valve body; a suppressing means for maintaining a valve switching surface in contact with the valve element at an appropriate contact surface pressure; and a second valve closing motion mechanism that generates a phase difference for valve switching between the two valve bodies. It is constructed to balance the hydraulic thrust acting on the switching surface.

[Effect]

According to the above configuration, when the input shaft is rotated by operating the handle, @1 valve body rotates, and then @2 valve body is rotated with a predetermined angular deviation to perform valve switching operation. , operating the metering pump to convert the pressure oil sent from the external pump into an oil amount equal to the steering amount and supplying it to one hydraulic chamber of the selected power cylinder via the valve body; The oil in the hydraulic chamber is returned to the tank via the valve body. At this time, external pump pressure acts on the end surface and back surface of each valve body, but since the area of the surface that generates hydraulic thrust of each valve body is equal, the hydraulic thrust from the surface is canceled out, and the end surface of the valve body That is, no frictional force is generated on the pulp switching surface due to hydraulic thrust. therefore,
The handle is lighter and easier to operate.

〔Example〕

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 shows the switching pulp section and metering pump of the all-hydraulic power steering system. The pulp housing 10 has a bottomed cylindrical hole with one end open, and a shaft hole for supporting the input shaft 20 is provided at the bottom of the hole. A plurality of spaced annular grooves 23, 26.3 are provided on the inner peripheral surface of the hole.
2 is formed. As shown in FIG. 2, four ports 14 to 17 are provided on the outer surface of the valve housing 10, and each port is connected to a pump 1 for supplying pressure oil.
, the left and right hydraulic chambers 4A and 4B of a power cylinder 4 incorporated in the wheel steering system, and a tank 5 that accommodates return oil from the hydraulic chambers are connected by piping, respectively. The power cylinder bow) 14, 15 and the tank port 17 are communicated with an annular groove 23, 26, 32 in the housing, and the pump port 16 is opened on the inner peripheral surface of the hole.

A disc-shaped valve body is rotatably fitted inside the valve housing 10. This disc-shaped valve body has a first valve body 36 that is directly connected to the input shaft 20, which will be described later, and an end face that slidably contacts the end face of the first valve body, and an engagement recess 93 for receiving rotational power. and a second valve body 39 provided with. The joint end surfaces of both the valve bodies constitute a pulp switching surface.

An input shaft 20 connected to the handle shaft is rotatably supported in the shaft hole of the valve housing 10, and the input shaft is provided with a connecting portion 20A with the handle shaft at one end,
It consists of a flange portion 20B located inside the housing and a cylindrical portion 20C extending inward from the flange portion.

The seventh rank portion 20B is in contact with the back of the first valve body 36,
They are integrated by a bin 86. The cylindrical portion 20C of the input shaft is located inside the 36 inner diameter through holes of the first valve body 36, and incorporates support means for a pump drive shaft 3A of the metering pump 3 and valve switching means, which will be described later.

On the other hand, a gerotor-type metering pump 3 is attached to the open end surface of the valve housing 10 by a fixing means 3B. This metering pump 3 is composed of a spacer 13 located on the pulp housing side, a metering pump section, and an end plate 3C that closes the other open surface of the metering pump section. The metering pump section 3 includes a stator 3D and an internally toothed rotor (not shown).
The star-shaped rotor 3E has one less external tooth than the rotor, and the oil passage of the second valve body 39 is connected between each tooth of the internal tooth rotor through a spacer 130 oil passage 80 as shown in FIG. It is connected to 47°48. The star-shaped rotor 3E is spline-coupled 3F to three eccentric metering pump drive shafts, and performs a metering action while rotating and revolving within the externally toothed rotor by eccentric rotation of the metering pump drive shaft. The three metering pump drive shafts pass through 13 through holes (inner diameter) of the spacer 130 and 39 through holes (inner diameter) of the second valve body, and extend into the cylindrical portion 20C of the input shaft. A tapered bottle hole 80 having a center line perpendicular to the shaft center line is bored at the end of the cut groove. On the other hand, the cylindrical portion 20C of the input shaft is provided with a pair of upper and lower loose fitting holes 81A and 81B that are located on the center line of the small diameter side of the bottle hole and expand toward the outside of the cylindrical portion. A sleeve 90 is fitted between the cylindrical portion 20C of the input shaft and the inner surface of the through hole 36A of the first valve body, and this sleeve 90 has three engaging protrusions 90A and A pair of upper and lower notches 91A and 91B, one of which is open, is provided at the rear end of the first valve body. The sleeve 90 supports both ends of a support pin 820 that protrudes through the bottle hole 80 of the metering pump drive shaft and the loose fitting holes 81A and 81B of the cylindrical portion.

Furthermore, the cylindrical portion of the input shaft is provided with a notch 91 of the sleeve.
A pair of spring holes 92A and 92B (see Fig. 3) are bored opposite to A and 91B, and the notch part of the sleeve and the spring hole of the cylindrical part are provided with holes as shown in Figs. 3(a) and 3(b). A plate spring 87 as shown is interposed. Therefore, when the input shaft 20 rotates, the leaf spring 87 is bent to a predetermined angle θ, as shown in FIG. As the sleeve 900 rotates, the second valve body 39 engaged with the sleeve rotates to perform a valve switching operation, and at the same time, the pump drive shaft 3A is rotated to operate the metering pump 3.

Here, the cylindrical portion 20C1 of the input shaft, the plate spring 87, the sleeve 90, the engagement protrusion 90A, and the engagement recess 93 constitute a second valve body rotation mechanism, and the cylindrical portion 20C1 of the input shaft, the plate spring 87, , the sleeve 90, the support pin 82, and the pump drive shaft constitute a pump drive mechanism of the metering pump.

A plurality of bottomed holes are bored in the back surface of the first valve body, and a suppressing means 94 such as a spring is provided between the holes and the flange portion 20B of the input shaft, so that the first valve body is always body @
The valve is pressed in the direction of the two valve bodies to apply appropriate contact surface pressure to the valve switching surfaces of both valve bodies.

Note that 95 is a thrust bearing, and 96 is an oil path for collecting leaked oil within the device.

Next, the pulp structure of the first valve body and the second valve body will be explained based on FIGS. 4 and 5.

As shown in FIG. 4, the first valve body 36 has a through hole 3 in the center.
6A, and three sets (I to ■) of lands and oil passages are formed on the end face.

Hereinafter, only one set of land and oil passage will be explained, and the explanation of the ground assembly will be omitted.

When the handle is in the neutral position and the supply of pressure oil to the power cylinder is stopped, the tank land 34 and the pump side are connected to the oil passage 33 on the tank side for directly connecting the pump 1 and the tank 5. An oil passage 38 is provided. The oil passage 38 is also used to connect the pump 1 and the metering pump 3 when turning left and right.

In addition, the oil passage 37 has the function of connecting the metering pump and the hydraulic chamber 4A for rightward movement of the rod of the power cylinder during cloth cutting; A land 28 and an oil passage 4 provided on the second valve body side, which will be described later, to connect the chamber 4A.
It has the function of inheriting 0. Furthermore, the land 25 and the oil passage 24 are connected to the hydraulic chamber 4B of the power cylinder. And■
During cloth cutting, the tank port 33A, the tank land 35, and the hydraulic chamber (low pressure chamber) 4B of the power cylinder are connected by the land 40 of the second valve body, which will be described later.
It wraps with the land 41 of the valve body (from which hydraulic oil metered by the metering pump 3 is pumped out), and the hydraulic oil is sent to the power cylinder.

Further, the first valve body 36 is provided with a radial step 200 located in an annular groove 32 formed on the inner circumferential surface of the valve housing 10 and communicating with the tank 5.
It is formed on an outer peripheral surface with a larger diameter on the end face side and a smaller diameter on the back side. An oil passage 3 communicating with a tank land 35 opening into the annular groove 32 is provided on the outer peripheral surface of the first valve body.
3 and an outlet of the oil passage 24 that communicates with the land 25 that opens into the annular groove 23 that communicates with the right hydraulic chamber 4B.

As shown in FIG. 5, the second valve body 39 is provided with a through hole 39A having a smaller diameter than the spacer 130 through hole 13A in the center, and the through hole 39A of the first valve body is passed through the through hole of the first valve body on the end surface side of the through hole. An annular recess 39B is formed into which a protruding portion of the cylindrical portion 20C of the input shaft protrudes toward the second valve body. This annular recess 39B has a depth such that an oil passage 39C is formed between the bottom of the recess and the end surface of the cylindrical portion of the input shaft.

A part of the annular recess is provided with an engagement recess 93 that is engaged with the engagement protrusion 90A of the sleeve 90.

The end face of the second valve body has three sets (■ to ■) of lands and oil passages for performing valve switching operation by cooperation with the lands and oil passages provided on the end face of the first valve body. It is formed. Hereinafter, a description will be given of items related to one set used when explaining the first valve body. A pump land 31 for connecting the pump 1 and the tank 5 and a land 31A communicated with the pump land are provided, and the handle is in a neutral position and the supply of pressure oil to the power cylinder is stopped. Sometimes, the pump land 31
and the tank land 34 of the first valve body are connected via the land 31A to form a circulation oil path that returns the pressure oil sent from the pump 1 to the tank 5 without sending it to the metering pump. First and second metering pump lands 41 and 43 for connecting the pump and the metering pump, and the metering pump and the left and right power cylinder hydraulic chambers, and the hydraulic chamber side 4 when the power cylinder rod moves to the right.
A land 28 is provided. When turning to the left, the pump land 31 and the first metering pump land 41 are communicated through the oil passage 38 of the first valve body, and at the same time, the second metering pump land 43 and the land 25 of the first valve body are communicated, Pump 1, metering pump 3, and left hydraulic chamber 4B are connected. On the other hand, when turning right, the pump land 31 and the second metering pump land 43 are communicated through the oil passage 38 of the first valve body, and at the same time, the first metering pump land 41 is communicated with the second metering pump land 43 through the oil passage 37 of the first valve body. The land 28 on the right hydraulic chamber side is communicated with the pump 1, the metering pump 3, and the right hydraulic chamber 4A. Furthermore, a land 28 and an oil passage 40 are provided on the right hydraulic chamber side for connecting the right and left hydraulic chambers 4A, 4B and the tank 5, and when turning right, the first valve body is connected to the first valve body through the oil passage 40. The land 25 and the tank land 35 are connected, and the left hydraulic chamber 4B and the tank 5 are connected.
While communicating the oil passage 37 of the valve body with the oil passage 40,
The oil passage 37 and the tank land 35 are communicated via the oil passage 40, and the right hydraulic chamber 4A and the tank 5 are connected.

An oil passage 2 is provided on the outer peripheral surface of the second valve body in alignment with an annular groove 26 connected to the right hydraulic chamber formed in the valve housing 10.
7 is provided, and an annular notch is formed that communicates with the pump port 16 and opens on the back side of the valve, and this annular notch is surrounded on the back side by a spacer 13 to form an annular groove 29. are doing. The annular groove 29 is communicated with a central through hole 39A through an oil passage 30.

Inside the second valve body, as shown in FIG. A passage 46 is formed, and both collecting oil passages 45° 46 are arranged in a plane perpendicular to the axis of the valve body. The first collecting oil passage 45 is an oil passage 42 that leads to the first metering pump land 41.
and an oil passage 47 having a larger diameter than the oil passage 42 leading to the metering pump 3, and the second collection oil passage 46 is connected to the metering pump 3.
An oil passage 44 leading to the second metering pump land 43 and an oil passage 48 having a larger diameter than the oil passage 44 leading to the metering pump 3 are communicated with each other.

Next, a description will be given of means for equalizing the high pressure on the pump side that acts on the first valve body 36 and the second valve body 39. 1st
The valve body is provided with a diameter step 200 with a smaller diameter on the back side to reduce the pressure receiving area, and the second valve body is provided with a diameter step 200 with a smaller diameter on the back side to reduce the pressure receiving area. In addition to providing a pocket 204, a back portion 201 is provided on the back side that is exposed to the high pressure oil passage due to a radial step difference between the through hole 13A and the through hole 39A of the spacer. And the first
An annular surface 20 is provided on the outer peripheral edge of the end face of the valve body and the second valve body.
3 is formed, and an opening for an oil passage 202 for guiding pressure oil from the pump is provided on the inner surface of the pulp housing facing this annular surface.

The operation of the above embodiment of the present invention will be explained.

When the handle is operated to rotate the input shaft 20, the first valve body 36 rotates at the same time since it is integrated with the input shaft. On the other hand, since the second valve body 39 is rotated via an elastic transmission member consisting of a plate spring 87 interposed between the cylindrical portion 20C of the input shaft and the sleeve 90, a predetermined distance is established between the second valve body 39 and the first valve body. A phase difference occurs. That is, when the handle is rotated to the right or left, the valve switching surfaces of both valve bodies slide by a predetermined angle to perform a valve switching operation, and rotate while maintaining this state. At the same time, the pump drive shaft 3A rotates eccentrically through the sleeve 90, and the metering pump 3 is activated.

Therefore, the pressure oil from the pump 1 is converted by the metering pump 3 into an oil amount equal to the rotation of the input shaft, that is, the amount of steering, and is passed through both the valve bodies to the left or right hydraulic chamber 4A, 4B of the power cylinder. supply to.

The oil circuit corresponding to the handle operation will be explained below.

First, when the handle is not turned, the lands and oil passages are arranged as shown in FIG. The pump land 31, the land 31A, the tank land 34, the oil passage 33, the annular groove 32, and the tank 5 are connected, and the pressure oil sent from the pump is simply circulated and is not supplied to the metering pump 3. Therefore, the power cylinder 4 is maintained at the neutral position. On the other hand, when turning to the right, the switch is made as shown in FIG. 8 (b). In this state, pump 1 - pump port 16 - annular groove 29 - oil passage 3
〇-Through hole 39A-Pump land 31-Oil passage 38-Second
Metering pump land 43 - oil path 44 - first collecting oil path 46 - oil path 48 - spacer oil path 80 - metering pump 3 - spacer oil path 80 - oil path 47 - flc2 collecting oil path 45 - oil path 42-1st pump plug/do 41-oil line 3
7-Land 28-Oil passage 27-Annular groove 26-Right hydraulic chamber 4A
, and an oil circuit consisting of the left hydraulic chamber 4B, the annular groove 23, the oil passage 24, the land 25, the oil passage 40, the tank land 35, the oil passage 33A, the annular groove 32, and the tank 5. The metering pump 3 converts pressure oil into an amount equal to the steering amount and sends it to the right hydraulic chamber of the power cylinder, moves the piston to the right, and generates the assist force necessary for clockwise steering via the piston's rod. I am getting . On the other hand, oil sent out from the left hydraulic chamber 4B as the piston moves is collected into the tank 5.

Further, when turning to the left, the switch is made as shown in FIG. 8(C). In this state, pump 1 - pump port 16 - annular groove 29 - oil passage 30 - through hole 39A - pump land 31 - oil passage 38 - first metering pump land 41 - oil passage 42
-Second collecting oil passage 45-Oil passage 47-Spacer oil passage 80-
Metering pump 3 - Spacer oil path 8 - Oil path 48
- First collecting oilway 46 - Overnight passage 44 - Second metering pump lands 4 and 3 - Land 25 - Oilway 24 - Annular groove 23 -
The oil circuits of the left hydraulic chamber 4B, the right hydraulic chamber 4A, the annular groove 26, the oil passage 27, the land 28, the oil passage 37, the oil passage 40, the tank land 35, the oil passage 33A, the annular groove 32, and the tank 5 are formed. , the pressure oil from the pump 1 is converted into pressure oil in an amount equal to the steering amount by the metering pump 3, and sent to the left hydraulic chamber 4Bk of the power cylinder, and the piston is moved to the right, and the piston is rotated counterclockwise via the rod of the piston. Obtains the assist power necessary for steering. On the other hand, as the piston moves, the right hydraulic chamber 4
The oil sent out from A is collected in tank 5.

Next, the action of the pump side high pressure on the valve switching surface will be explained.

The high pressure on the pump side acts on the oil passage, land, shaft, back surface, etc. of each valve body, and generates hydraulic thrust in the direction of the valve shaft.
4 and the annular surface 203 on the outer peripheral edge of the valve switching surface, the hydraulic thrust acting in the direction of the valve switching surface and the hydraulic thrust acting in the opposite direction to the aforementioned direction are equal,
Only the force exerted by the suppressing means 94 provided on the first valve body side acts on the valve switching surface. Therefore, the rotational torque of the valve body is reduced, and the operability of the handle is improved.

Note that FIG. 9 shows an emergency circuit when the pump 1 does not operate (failure, etc.). When the pump 1 is operating normally, the steel ball 100 is pressed against the seat surface 101 by the high pressure oil from the pump port 16, and there is no short circuit of the high pressure oil to the tank port 17. on the other hand,
When the pump is not operating, it is necessary to manually pump up the hydraulic oil in the circuit up to the power cylinder 4 with HP 8 or less. In this case, there is no high pressure oil to push up the steel ball 100, so the tank port 17 and pump port 16 are connected. The required hydraulic fluid flows back from the tank port to the pump port. The pin 102 is provided to prevent the steel ball from descending to the lowest end of the oil passage 103.

〔Effect of the invention〕

As described above, according to the present invention, since the valve body structure is made into a disk shape, the valve body can be easily machined and the machining accuracy can be improved.
Since a hydraulic thrust equalizing means such as a high pressure acting surface is provided, the hydraulic thrust due to the pump side high pressure acting on the valve overlapping surface becomes extremely small, improving the operability of the handle.

[Brief explanation of drawings]

FIG. 1 is a vertical sectional view of the switching pulp section and metering pump of the fully hydraulic power steering device according to the present invention, FIG. 2 is an external view of the pulp housing, and FIG. 3 is a diagram showing the transmission mechanism.
(a) shows when the vehicle is neutral, and (b) shows when it is turned to the left. FIG. 4 is a diagram showing the valve switching surface of the first valve body, FIG. 5 is a diagram showing the valve switching surface of the second valve body, and FIG. 6 is a sectional view taken along the line Xl-X in FIG. Figure 7 is a cross-sectional view taken along X, -X in Figure 1;
Figures (a), (b), and (c) are diagrams showing the valve switching states, (
A) indicates when the vehicle is neutral, (B) indicates when turning to the right, and (C) indicates when turning to the left. FIG. 9 is a diagram showing an emergency circuit, and FIG. 10 is a system diagram of a fully hydraulic power steering device. DESCRIPTION OF SYMBOLS 10... Pulp housing, 3... Metering pump, 20... Input shaft, 36... First valve body, 39...
...Second valve body, 90...Sleeve, 90A...Engagement protrusion, 93...Engagement recess, 94...Press means.

Claims (1)

[Scope of Claims] A valve housing having ports connected to each hydraulic chamber of the power cylinder, an external pump, and a tank on the outer peripheral surface, a bearing at the front and an internal pump mounting seat at the rear, and the internal pump mounting seat. , a metering pump that converts pressure oil sent from an external pump into an oil amount equal to the steering amount and supplies it to each hydraulic chamber of the power cylinder; and an input shaft supported by the bearing and having a connection portion with the handle shaft. , a pump drive mechanism that drives the metering pump in synchronization with rotation of the input shaft; a first valve body fixed to the input shaft and having a valve switching surface perpendicular to the axis; and the first valve body. placed between the valve body and the metering pump,
A second valve element, which is fixed to the pump drive mechanism and has a valve switching surface that switches the oil passage in cooperation with the first valve element, and the valve switching surface where the two valve elements come into contact are subjected to an appropriate contact surface pressure. a pressing means for holding the input shaft at a predetermined angle;
a second valve body rotation mechanism that generates a phase difference for valve switching between the second valve body and the first valve body, and a pressure receiving surface that generates hydraulic thrust due to pump side high pressure for each of the valve bodies; A fully hydraulic power steering device configured to equalize the areas of the valve elements and balance the hydraulic thrust acting on the valve switching surfaces of both valve bodies.