JPS59726B2 - hydraulic operating device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a hydraulic operating device for operating an operated object such as a spool of a direction switching valve using a pressure reducing valve type remote controlled valve.

Next, a hydraulic system for operating a direction switching valve using a conventional pressure reducing valve type remote control valve will be explained with reference to FIG.

A push rod body 2, a sleeve 3, a connecting push rod 4, and a spool 5 are housed in a valve body 1 of a pressure reducing valve type remote control valve (hereinafter referred to as a remote control valve) R so that they can move in the axial direction while being connected to each other. A balance spring 6 is provided between the sleeve 3 and a spring receiver formed at one end of the connecting push rod 4, and a balance spring 6 is provided between the end surface of the spool 5 on the side opposite to the connecting push frame and the inner wall surface of the valve body 1. A return spring 1 is attached to.

The spring force of the balance spring 6 is set larger than that of the return spring I.

The valve body around the spool 5 has a pressure oil supply port 8,
9 and 10 are formed, the pressure oil supply port 8 communicates with a passage 11 on the oil pressure source side, and the tank port 10 communicates with a passage 12 on the oil tank side.

The passage 11 is connected to the discharge side of the hydraulic pump 13.
2 is connected to the oil tank 14.

Further, the output port 9 and the back pressure chamber 15 in which the return spring 1 is housed are connected through a passage 16.

A lever 17 for operating the push rod body 2 is swingably attached to the wall of the valve body 1.

Note that the push rod body 2 and the above-mentioned parts related thereto are provided on the left and right sides.

A spool 19 is housed in the valve body 18 of the direction switching valve S so as to be slidable in the axial direction, and ports 20 to 24 are formed in the valve body around the spool 19.

Port 20 is connected to the discharge side of hydraulic pump 25, port 23.
24 is the oil tank 14, port 21 is the actuator,
For example, the port 22 is connected to the chamber on the anti-rond side of the hydraulic cylinder 26, and the port 22 is connected to the chamber on the rond side of the hydraulic cylinder 26.

A pair of spring receivers 27a, 2 are provided at both ends of the spool 19.
7b, 27a', 27b' are attached, and a spring 28, 28' is provided between each set of spring receivers.

The back pressure chamber 15 of the remote control valve R is connected to the operation pressure chamber 31.3 in the valve body 1B of the directional control valve 5 by an oil guide pipe 29.30.
1'.

When the lever 17 is tilted in the direction of the arrow, the end of the lever 17 pushes the push rod body 2 downward by an amount Z, and at the same time, the sleeve 3 is also pushed downward, and the dynamic spool 5 is returned and pressed against the connecting push rod 4 by the spring 7. In addition, the connecting push rod 4 receives a downward force from the balance spring 6, and the spring force of the balance spring 6 is set to be larger than that of the return spring 1, so that the push rod body 2 When a displacement of Z is applied to the sleeve 3, the sleeve 3, the connecting push rod 4, and the spool 5 overcome the reaction force of the return spring 7 and move downward as one.

Depending on the amount of movement of the spool 5, the opening degree of the constriction between the annular recess 5a of the spool 5 and the pressure oil supply port 8 is determined. are in communication, and the pressure oil from the hydraulic pump 13 passes through the passage 11, the constriction between the spool 5 and the pressure oil supply port 8, the output port 9, the passage 16, the back pressure chamber 15, and the oil guide pipe 29, and then operates the direction switching valve S. It flows into the pressure chamber 31.

This overcomes the setting force of the springs 28.degree. 28' and causes the spool 19 to slide to the right.

At this time, the oil in the operating pressure chamber 31' on the opposite side is supplied to the oil guide pipe 30,
Opposite back pressure chamber 15, passage 16, port 9, port 10
, flows through the passage 12 to the oil tank 14.

If the amount of movement of the spool 19 becomes y in this way, then
In the operating pressure chamber 31, the spring 28,28' increases the hydraulic pressure p2.
increases to a predetermined pressure depending on the amount of operation of the operating lever,
The pressure is transmitted to the chamber 15 through the oil guide pipe 29, and acts on the spool 5 of the remote control valve R as oil pressure p1.

As a result, the spool 5° connecting push rod 4 overcomes the balance spring 6 and is pushed up, the constriction between the spool 5 and the pressure oil supply port 8 is closed, and the flow of pressure oil from the passage 11 to the output port 9 side is prevented. will be cut off.

On the other hand, in the direction switching valve S, the constriction part is opened by the movement amount y of the spool 19, and a part Q of the pressure oil from the hydraulic pump 25 flows into the chamber on the opposite side of the hydraulic cylinder 26.
A load is driven at a certain speed V.

In this way, in response to a certain operating angle of the lever 11, the output pressure p1 of the remote control valve R and the spool 1 of the direction switching valve S are adjusted.
9 movement amount y1 Amount of pressure oil flowing through the main circuit Q, load speed V
will be obtained.

When the lever 11 is returned to the neutral position, the downward pressing force on the push rod body 2 is removed, so the sleeve 3 and the connecting push rod 4 are integrated by the balance spring 6, and these and the spool 5 are returned to their original positions by the return spring 7. be restored to the state.

In this state, the pressure supply port 8 of the remote control valve R is closed and the tank port 10 is opened, so the oil guide pipe 29
The oil in the back pressure chamber 15 is discharged into the oil tank 14 through the throttle part on the tank port 10 side by the force of the spring 28 pushing the spool 19, and the directional switching valve S returns to the neutral position.

Therefore, the pressure oil flowing from the hydraulic pump 25 to the hydraulic cylinder 26 through the throttle part of the directional switching valve S is blocked, and the movement of the load is stopped.

The above-mentioned remote control valve has the advantage that the operating force is small compared to a directional control valve that operates using a mechanical linkage mechanism, and the disadvantage that there is a large response delay because it is operated via oil.

I will discuss the response delay in detail.

Figure 2 shows the oil pressure p2 in the operating pressure chamber 31, the oil pressure p1 in the back pressure chamber 15, and the throttle area between the spool 5 of the remote control valve R and the pressure oil supply port 8 when the lever 11 is suddenly operated by Z. It shows how the amount of movement y of the spool 19 of the inflow area a1 direction switching valve S changes with respect to time.

The reason for this is as follows.

If the lever 17 is used to rapidly push the push rod 2 by Z, at the same time (ignoring the dead zone) the above-mentioned inflow area a
opens to its maximum value, and the oil pressure p□ also rises rapidly due to downstream pipe resistance and the like.

Therefore, the spool 5 of the remote control valve R is rapidly pushed back by the oil pressure p1, overcoming the balance spring 6.
The inflow area a also becomes almost zero in a short time Δt.

On the other hand, the spool 1 of the direction switching valve S passes through the oil guide pipe 29
The flow rate q that presses 9 is expressed as q=Ca, /Ti7''...(1).

However, C is a constant -1) o is the pressure in the passage 11.

If a decreases to near zero in a short time, the flow rate q also decreases rapidly, and therefore the directional switching valve S expressed by the following equation (2)
The amount of movement y of the spool 19 is a certain target value y.

It takes a long time to reach nd.

y=A/qdt...(2) However, A
is a constant.

If we rephrase this, we get the following.

Immediately after pushing in the push rod body 2 of the remote control valve R,
The spool 19 of the direction switching valve S is at the target value y.

Therefore, before the oil pressure p2 in the operating pressure chamber 31 reaches the target value p2end, the oil pressure p□ on the chamber 15 side suddenly rises due to pipe resistance, etc., and the oil pressure p1 of the remote control valve R This pushes up the spool 5 and rapidly narrows down the inflow area a.

As a result, the time required to reach yIJ″' yend becomes longer.

In view of the above-mentioned conventional drawbacks, the present invention provides that, before the pressure in the operating pressure chamber of an operated object such as a spool of a directional control valve reaches a predetermined value, a flow from a pressure reducing valve type remote control valve to an operating pressure chamber of an operated object such as a spool of a directional switching valve is provided. The purpose is to prevent the flow rate from rapidly decreasing and the time required for the operated object to move by a predetermined amount to be prolonged.

To achieve this object, the present invention provides a spring means that is compressed according to the amount of operation of an operating lever, a spool that moves via this spring means, and a pressure that is formed in the spool and the valve body depending on the amount of movement of the spool. The oil supply port has a throttle part whose opening degree is determined, and pressure oil from the hydraulic source is supplied to the operation pressure chamber of the operated object through the throttle part, an output port formed in the valve body, and a conduit. A pressure reducing valve type remote control valve is provided, and when the operated body is moved by a predetermined amount according to the amount of operation of the operating lever by the hydraulic pressure acting on the operating pressure chamber, the hydraulic pressure in the operating pressure chamber becomes a predetermined pressure, In a hydraulic operation system that acts on the spool through a back pressure chamber to close the throttle part, the output port of the valve body and the operation pressure chamber of the operated body are connected by a first pipe line. In addition, the back pressure chamber and the operation pressure chamber of the operated body are connected by a second pipe line.

First, an embodiment of the present invention shown in FIG. 3 will be described.

In this figure, the same parts as in FIG. 1 are given the same reference numerals, and the hydraulic pumps 13, 25, hydraulic cylinder 26, etc. in FIG. 1 are omitted.

The remote control valve R and the directional control valve S are oil guide pipes that flow oil to move the directional control valve spool, and statically feed back hydraulic pressure corresponding to the amount of movement of the directional control valve spool to the remote control valve. They are connected to each other by an oil guide pipe for pushing back the spool.

That is, the output port 9 of the remote control valve R is connected to the operation pressure chamber 31.3 of the directional control valve S by the oil guide pipe 32.33, respectively.
The back pressure chamber 1 of the remote control valve R is connected to the left end and right end of 1'.
5 are connected to the intermediate portion of the operating pressure chamber 3L31' of the direction switching valve S by oil guide pipes 34 and 35, respectively.

The operation after the lever 1γ is pushed down and the push rod body 2 is pushed in is almost the same as the conventional one, but since the oil guide pipes 32 and 33 and the oil guide pipes 34 and 35 are separate, the oil can be led from the remote control valve R. Pressure oil flows into the operating pressure chamber 31 of the directional switching valve S through the oil pipe 32, and due to the pipe resistance on the downstream side of the throttle part (oil guide pipe 32) between the spool 5 and the pressure oil supply port 8, the part after the throttle part is Even if the hydraulic pressure suddenly rises, the hydraulic pressure in the back pressure chamber 15 that acts to push back the spool 5 and close the throttle between the spool 5 and the pressure oil supply port 8 is maintained by the sudden rise in hydraulic pressure in the area behind the throttle. It rises later than the rise in response to the rise in the operating pressure chamber of the directional switching valve S.

Therefore, the inflow area of the pressure oil in the throttle part does not suddenly decrease, and the response time of the spool 19 of the direction switching valve S (the time from when the input displacement Z is given to when the predetermined output displacement y is obtained) ) is shortened.

FIG. 4 shows the amount of movement y1 of the spool 19 in this embodiment.
Hydraulic pressure p2. p1 shows the relationship between the inflow area a1 pushing amount Z and time.

In other words, since the time Δt during which the inflow area a is largely open is large, the flow rate q expressed by equation (1) also becomes large,
Therefore, the target value yend is given by the amount of movement y of the spool 19.
The time it takes to reach is also shortened.

FIG. 5 shows another embodiment of the present invention, in which the same parts as in FIG. 3 are given the same reference numerals.

Output port 9 Same as the example of the rabbit, oil guide pipe 32.33
are connected to the operating pressure chambers 31 and 31', respectively.

It acts on the spool 5 of the remote control valve R to throttle the inflow area a (the back pressure chamber 15 and the output port 9 side are connected so that the hydraulic pressure p1 is generated later than the hydraulic pressure pH after the throttle section). A restrictor 37 is provided in the passage 36, and a passage 39 provided with a check valve 38 is connected to the passage 36.

When the operating lever 17 is suddenly operated and the push rod body 2 is pushed in, the pressure oil in the back pressure chamber 15 flows into the check valve 38.
The spool 5 is pushed down by escaping into the oil guide pipe 32 through the oil guide pipe 32, so that the input displacement 2 can be applied smoothly.

Further, the back pressure chamber 15 and the tank port 10 are connected by a passage 40, and a check valve 41 is provided in the middle of the passage 40, so that when the operating lever 17 is returned to the neutral position, the passage 12, By sucking oil from the oil tank into the back pressure chamber 15 through the tank port 10 and preventing a vacuum phenomenon in the back pressure chamber 15, the input displacement 2 is smoothly released.

After knocking down the lever 17 and pushing in the push rod body 2, tM'
Il = is almost the same as the conventional one, but since the feedback oil pressure signal p1 is made to rise later than the oil pressure p1 on the output port 9 side, the inflow area a is
As shown in FIG. 4, the time Δt required for y to reach o is larger than that in FIG.

According to the present invention described above, it is possible to shorten the response delay when operating an operated object such as a spool of a directional valve or a swash plate of a variable discharge amount cedar hydraulic pump using a remote control valve.

[Brief explanation of the drawing]

FIG. 1 is a sectional view showing a system for operating a directional control valve using a conventional remote control valve, FIG. 2 is a diagram showing response waveforms in the system shown in FIG. 1, and FIG. 3 is a diagram showing an embodiment of the present invention. A sectional view, FIG. 4 is a diagram showing the response waveform in the embodiment of FIG. 3, and FIG.
The figure is a sectional view showing another embodiment of the present invention. R...Pressure reducing valve type remote control valve, 8...Direction switching valve, 2...Push rod body, 5...Spool, 6... °°Equilibrium spring, 7...Return spring, 8...Pressure oil supply port, 9...
Output port, 10...tank port, 11゜1
2... Passage, 13... Hydraulic pump, 1
4...Oil tank, 15...Back pressure chamber, 1
7... Lever, 19... Spool, 2
0 to 24...Port, 25...Hydraulic pump, 26...Hydraulic cylinder, 31, 31'.
...Operating pressure chamber, 32, 33... Oil guide pipe, 34° 35... Oil guide pipe, 36... Passage, 39... Passage, 40...Aisle, 41
······non-return valve.

Claims (1)

[Claims] 1 A spring means that is compressed according to the amount of operation of the operating lever, a spool that moves via this spring means, and an opening degree between the spool and a pressure oil supply port formed in the valve body is determined by the amount of movement of the spool. A pressure-reducing valve type remote control valve has a constriction section, and allows pressure oil from a hydraulic source to act on an operating pressure chamber of an operated object through the constriction section, an output port formed in a valve body, and a conduit. When the operated object moves by a predetermined amount according to the operating amount of the operating lever due to the hydraulic pressure acting on the operating pressure chamber, the hydraulic pressure in the operating pressure chamber becomes a predetermined pressure, and the pressure is applied to the spool via the back pressure chamber. In the hydraulic operation system, the output port of the valve body and the operation pressure chamber of the operated body are connected by a first conduit, and the back pressure chamber and the 1. A hydraulic operating device, characterized in that an operating pressure chamber of an operating body is connected to the operating pressure chamber through a second conduit.