JPH0914203A - Controller for hydraulic actuator - Google Patents

Abstract

PURPOSE: To prevent a hydraulic equipment such as a hydraulic actuator from being resonated by pulsation generated from the vibration generating source of an oil pressure pump, by a structure which is manufactured at a low cost, simple and can be miniaturized. CONSTITUTION: A check valve 14 into which a valve piece 16 which is delicately displaced so as to prevent flow motion of pressure oil to a reverse direction as well as to allow the fluid motion of the pressure oil to a hydraulic controller side, is built in its floating condition, is intervened in a pressure oil input circuit 8 on the oil pressure pump side of a hydraulic controller 4.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a control device for a hydraulic actuator.

[0002]

2. Description of the Related Art For example, in a hydraulic control device for controlling a hydraulic actuator such as a power steering device for steering a vehicle, when pressure oil is supplied from the hydraulic pump, the pressure oil peculiar to the hydraulic pump is changed. Since the pressurizing operation of No. 1 has pulsation, the pulsation causes vibration in hydraulic equipment such as a hydraulic actuator driven by the supply pressure.

In the conventional structure, a resonance phenomenon occurs when the vibration frequency of the pulsation and the vibration characteristics of the equipment such as the valve coincide with each other, so that the hydraulic equipment or the like has an unreasonable amplitude. There were problems such as various vibrations, chattering phenomena, and abnormal sounds.

Therefore, conventionally, in order to prevent such a resonance phenomenon, a means for changing the vibration characteristic of a device having a fear of occurrence of the resonance phenomenon by a chamfer, a diaphragm, or the like, or for absorbing pulsation is used. The damper was installed in the oil passage to the equipment.

[0005]

However, when the means for changing the vibration characteristics of the equipment by forming a chamfer or a diaphragm is applied as described above, the function originally required for the equipment is required. There is also a problem that the function of the device is degraded and there is a case that the functional degradation of the device is not allowed, so it is not possible to form a chamfer or a diaphragm,
Either the prevention of the occurrence of the resonance phenomenon is abandoned, or the pulsation absorbing damper is provided as described above.

On the other hand, the means for providing the damper for absorbing pulsation is intended to prevent the occurrence of the resonance phenomenon by weakening the pulsation itself which is the source of the resonance phenomenon, but the damper is expensive and Since a large installation space is required, the cost is increased, and there is a problem that the installation space cannot be made compact because a sufficient installation space must be secured.

The present invention has been made in view of the above circumstances, and is an inexpensive, simple and compact method for preventing resonance of hydraulic equipment such as a hydraulic actuator due to pulsation generated from a vibration source such as a hydraulic pump. It is an object of the present invention to provide a control device for a hydraulic actuator that can be realized by a configuration that can be realized.

[0008]

According to a first aspect of the present invention, there is provided a control device for a hydraulic actuator, wherein a hydraulic oil input circuit on the hydraulic pump side of the hydraulic control device is provided with a flow of the hydraulic oil to the hydraulic control device side. It is characterized by interposing a check valve in which a valve element which is allowed to move and which is slightly displaced so as to prevent the pressure oil from flowing in the opposite direction is incorporated in a floating state.

According to a second aspect of the present invention, there is provided a hydraulic actuator control device according to the first aspect, wherein the check valve is incorporated in a pipe connecting fitting to a case of the hydraulic control device. Is a characteristic configuration.

According to a third aspect of the present invention, there is provided a hydraulic actuator control device, comprising: a hydraulic oil input circuit for the hydraulic control device;
A characteristic feature is that a branch passage is provided and an elastic hose having a closed tip is connected to the branch passage.

[0011]

The control device for the hydraulic actuator according to claim 1 of the present invention allows the pressure oil input circuit on the hydraulic pump side of the hydraulic control device to flow the pressure oil to the hydraulic control device side and in the opposite direction. Since there is a non-return valve that incorporates a valve that is subtly displaced to prevent the flow of pressure oil,
Even if there is a pulsation in the pressure oil supply from the hydraulic pump, the supply pressure to the hydraulic control device increases and the valve element allows the pressure oil to flow to the hydraulic control device side. When it is, the pressure oil that has passed through the oil passage of the check valve is smoothly supplied into the valve chamber, and thus the pressure oil is smoothly supplied into the hydraulic control device. On the other hand, even if the pressure of the pressure oil from the hydraulic pump temporarily becomes lower than the pressure of the hydraulic control device, the pressure difference prevents the valve from blocking the flow of pressure oil in the opposite direction. It is possible to prevent the pressure on the hydraulic control device side from being lowered due to being restricted in contact with the valve seat for the vehicle.

A control device for a hydraulic actuator according to a second aspect of the present invention is the control device for a hydraulic actuator according to the first aspect, wherein the check valve is incorporated in a pipe connecting fitting to a case of the hydraulic control device. Since the check valve does not have to be mounted separately from the pipe connecting fitting, a simple work is required, and the overall arrangement can be made compact.

According to a third aspect of the present invention, there is provided a hydraulic actuator control device, comprising: a hydraulic oil input circuit for the hydraulic control device;
Since a branch passage is provided and an elastic hose with a closed tip is connected to the branch passage, the elastic hose can absorb and absorb the pulsation from the hydraulic pump sufficiently by elastic expansion and contraction, but its structure is extremely simple. is there.

[0014]

According to the configuration of claim 1 of the present invention, even if a check valve having a valve element incorporated in a floating state is provided, even if the pressure oil from the hydraulic pump pulsates, the valve element The free displacement associated with the pulsation of the hydraulic control device suppresses the pulsation of the pressure oil in the trap, and the unreasonable resonance between the pulsation and the hydraulic control device is greatly suppressed, which is uncomfortable. There is an advantage that vibration noise and the like can be softened and cost can be reduced because the check valve to be installed has a simple structure.

According to the second aspect of the present invention, since the check valve is provided by being incorporated in the pipe connecting fitting, the work of installing the check valve is also used as the work of the pipe connecting fitting. The efficiency can be improved, and the installation space can be made small, so it can be made compact.

According to the third aspect of the present invention, the pulsation of the pressure oil from the hydraulic pump can be suppressed with a very simple structure in which the branch passage is simply provided and the elastic hose is provided at the branch passage. The cost can be reduced as compared with the conventional structure in which a damper or the like is provided, and the installation space can be reduced, so that the size can be reduced.

[0017]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 schematically shows an all-hydraulic power steering apparatus 1 as an example of hydraulic equipment. The all-hydraulic power steering device 1 is mounted on a work vehicle such as an agricultural tractor or a passenger vehicle. The all-hydraulic power steering system 1 includes a controller 4 to which a handle shaft 3 of a steering handle 2 is interlocked, a hydraulic pump 5 for supplying pressure oil to the controller 4, and a steering wheel using pressure oil from the controller 4. (Not shown) and a power cylinder 7 for steering operation.

Then, the pressure oil from the hydraulic pump 5 is supplied to the controller 4 via a piping hose 8 and a piping connection fitting 9 which constitute a pressure oil input circuit as a pressure oil input path. On the other hand, the controller 4 and the power cylinder 7 are connected via the piping hoses 10 and 10, and the power cylinder 7 is pushed and pulled by the pressure oil for steering from the controller 4.

As shown in FIG. 2, the pipe connection fitting 9 includes a controller-side mounting portion 9A having a screw portion formed so as to be screwed to the case 11 of the controller 4, a jig operating portion 9B for screwing the same. Joint 12 at the end of piping hose 8
And a hose mounting portion 9C for mounting the pipe structure. A check valve 14 that suppresses transmission of pressure oil pulsation from the hydraulic pump 5 to the controller 4 is provided in the oil passage 13 formed through the pipe connecting fitting 9. More specifically, as shown in FIG. 2, the diameter of the oil passage 13 at the controller side mounting portion 9A is set to be larger than the diameter of the oil passage 13 at the hose mounting portion 9C and the jig operating portion 9B. The stepped portion formed by the different diameters is set as the pressure oil inflow prevention valve seat 15. Then, on the inner peripheral wall of the oil passage 13 at the controller-side mounting portion 9A, the controller 4 of the sphere 16 as a valve element, which will be described later, is provided.
A female screw portion is formed for screwing the tubular regulation body 17 that regulates the movement to the side. Sphere 1 of this cylindrical regulation body 17
As shown in FIGS. 2 and 3, the 6-side end portion is provided with six slits 18 along the radial direction at a predetermined depth around the outer periphery thereof to form a spherical seat valve seat 19. ing.
As a result, the position of both the pressure oil inflow preventing valve seat 15 and the spherical body restricting valve seat 19 is restricted, so that both valve seats 1
A valve chamber 20 is arranged in the oil passage 13 between 5 and 19 so that the spherical body 16 can be floated so as to be capable of being slightly displaced in the flow direction. Therefore, as shown in FIG. 2, between the spherical body 16 and the pressure oil inflow prevention valve seat 15 when the spherical body 16 is regulated to abut on the spherical body regulation valve seat 19 so that the pressure oil supply is permitted. The clearance is set to a small width. The tubular restricting body 17 is screwed onto the pipe connecting fitting 9 while adjusting the restricting position of the spherical body 16 to an appropriate position, and the screwing and adjusting are performed on the side where the slit 18 is formed. This is performed by using the two slits 21 and 21 formed at the opposite ends.

With the above structure, even if there is a pulsation in the supply of the pressure oil from the hydraulic pump 5, the supply pressure to the controller 4 becomes high and the spherical body 16 is restricted to contact with the spherical body restricting valve seat 19. , The pressure oil that has passed through the oil passage 13 is the valve chamber 2
0 is smoothly supplied to the controller 4, and the pressure oil is smoothly supplied to the controller 4 through the slit 18. On the other hand, the pressure of the pressure oil from the hydraulic pump 5 is temporarily changed to the controller 4
Even if the pressure becomes lower than the pressure on the side,
Prevents the pressure on the controller 4 side from decreasing due to the contact with the pressure oil inflow preventing valve seat 15 being restricted. Therefore, large pulsation of the pressure of the pressure oil in the controller 4 is suppressed, and by extension, the controller 4 is suppressed from largely resonating due to the pulsation. As a result, the vibration and chattering phenomenon of the steering wheel 2 caused by the large vibration of the controller 4 are suppressed.

Next, an embodiment according to claim 3 of the present invention will be described. The description of the same structure as the embodiment according to claim 1 described above will be omitted, and the same reference numerals will be given.

As shown in FIG. 4, a T-shaped branch pipe 22 is connected in the middle of a piping hose 8 connecting the controller 4 and the hydraulic pump 5. A rubber pipe hose 24 as an elastic hose whose tip end is closed by a closing member 23 made of a blind plug is connected to a branch pipe portion 22A as a branch passage of the T-shaped branch pipe 22 by a joint 25. Therefore, the oil passage is in communication between the piping hose 8 and the rubber piping hose 24 via the T-shaped branch pipe 22.

With this configuration, even if there is a pulsation in the pressure oil supply from the hydraulic pump 5, when the supply pressure to the controller 4 is high, the pressure oil is normally supplied to the controller 4. On the other hand, when the pressure of the pressure oil from the hydraulic pump 5 temporarily becomes lower than the pressure on the controller 4 side, the pressure oil supplied into the rubber piping hose 24 flows out from the piping hose 8 due to the elasticity of the hose 24. Come on, piping hose 8
Among them, the pressure drop of the pressure oil in the controller 4 is suppressed. Therefore, a large pulsation of the pressure fluctuation of the pressure oil in the controller 4 is suppressed, and as a result, the controller 4 is suppressed from largely resonating due to the pulsation. Since the structure is also extremely simple, it can be constructed at low cost.

[Other Embodiments] The invention according to claim 1 and the invention according to claim 3 of the present invention may be provided together. In the above-mentioned embodiment, the sphere is used as the valve, but the valve is not limited to the sphere and may be a poppet or the like. The pressure oil input circuit is not limited to the piping hose and the pipe connecting fittings thereof as in the above embodiment, but is defined as the pressure oil input path between the hydraulic pump and the hydraulic control device. The check valve according to the present invention is not particularly limited in its installation location as long as it is in the pressure oil input passage. The hydraulic device is not limited to the power steering device, and the present invention can be applied to various hydraulic devices.

In the claims, reference numerals are provided for convenience of comparison with the drawings, but the present invention is not limited to the configuration shown in the attached drawings.

[Brief description of the drawings]

FIG. 1 is a schematic explanatory diagram of an all-hydraulic power steering system including the invention of claim 1.

FIG. 2 is a vertical sectional side view showing a main part of the invention of claim 1;

FIG. 3 is a perspective view showing a tubular regulator.

FIG. 4 is a schematic explanatory view of an all-hydraulic power steering system including the invention of claim 2.

[Explanation of symbols]

 4 Hydraulic control device 5 Hydraulic pump 8 Pressure oil input circuit 11 Case 14 Check valve 16 Valve 22A Branch path 24 Elastic hose

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Osamu Yagi 64 Ishizukitamachi, Sakai City, Osaka Prefecture Kubota Sakai Factory Co., Ltd.

Claims (3)

[Claims] 1. A hydraulic pump (5) of a hydraulic control device (4).
A valve (16) slightly displaced to allow the pressure oil input circuit (8) on the side to flow the pressure oil to the hydraulic control device (4) side and to prevent the flow of the pressure oil to the opposite direction. A control device for a hydraulic actuator, in which a check valve (14) having a built-in valve is interposed. 2. A control device for a hydraulic actuator according to claim 1, wherein the check valve (14) is incorporated in a pipe connection fitting (9) to the case (11) of the hydraulic control device (4). 3. The pressure oil input circuit (8) to the hydraulic control device (4) is provided with a branch passage (22A), and an elastic hose (24) whose tip is closed is provided with the branch passage (22A).
Control device for hydraulic actuator connected to.