JPS63186012A - Controller for switching valve in hydraulic actuator - Google Patents

Abstract

PURPOSE:To reduce any shock at the time of switching as well as enable the inching operation of a spool, by enabling the spool to be stopped even at the mid-position of switching. CONSTITUTION:A driving unit B for axially moving a spool 2 and a detecting unit C for detecting the position of the spool 2 and a respectively connected to both end portions of the spool 2, and then in the driving unit B is provided an electric motor 13 capable of arbitrarily stopping rotation. Therefore, the spool 2 can be arbitrarily stopped at the mid-position of switching so that the inching operation of the spool 2 can be performed and also any shock can be reduced at the time of switching.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a switching valve control device for controlling the drive of hydraulically operated equipment such as a hydraulic cylinder, and is used, for example, to control the drive of a dump cylinder in a dump truck.

(Prior Art) Conventionally, in a switching valve control device for driving and controlling a dump cylinder of a dump truck, for example, a spool is slidably inserted in a switching valve body having a plurality of fluid passages in an axial direction, and One end was linked via a wire to an operating lever installed in the driver's seat, and by manually operating this operating lever, the spool was moved and the fluid passages were switched. However, since a relatively large space is required inside the driver's seat for this control lever to be able to swing, there are restrictions when installing this control lever, and even if it can be installed inside the driver's seat where space is small, it cannot be operated. There was a problem that the lever was not easy to operate.

Therefore, in recent years, so-called electromagnetic valves have been developed that use the magnetic effect that occurs when current is passed through a solenoid to move the spool in a switching valve control device, and use this effect to move the spool and switch the fluid passage. Some vehicles are designed so that the box does not take up much space in the driver's seat and can be easily installed.

(Problems to be Solved by the Invention) However, although the above-mentioned solenoid valve allows the operation box to be easily installed in the driver's seat without taking up much space, the electric 6ff valve does not require much space in the driver's seat. Since the spool is moved, the spool can only take, for example, a switching position when the solenoid is energized or a neutral position when the solenoid is deenergized. That is, there is a problem in that it is impossible to perform a so-called inching operation, in which the spool is stopped at a position in the middle of being switched from the switching position to the neutral position.

(Means for Solving the Problems) A switching valve control device for hydraulically operated equipment according to the present invention is arranged between the hydraulically operated equipment and a hydraulic pump driven by a power extraction device that extracts power from a power source. A switching valve control device for controlling pressure oil from the hydraulic pump, wherein the switching valve control device includes a switching valve in which a plurality of fluid passages are made switchable by a spool that is slidable in the axial direction. The spool includes a main body, a drive unit that is linked to one end of the spool and moves the spool in the axial direction, and a detection unit that detects the position of the spool, and the drive unit has forward and reverse rotation controlled by an operating member. The spool is moved in the axial direction by the rotation of the electric motor, and the spool can be stopped at any position by arbitrarily stopping the rotation of the electric motor. be.

(Function) The rotation of the electric motor moves the spool, thereby switching the fluid passage. The direction and amount of movement of the spool are determined by the direction and amount of rotation of the electric motor, and the spool is stopped at an arbitrary position by stopping the rotation of the electric motor.

(Example) Hereinafter, one embodiment of the present invention will be described with reference to the drawings.

In this example, a switching valve control device for a hydraulically operated device according to the present invention, which is used in a dump truck, for example, will be explained.

Although not shown in the drawings, this dump truck has a hoist mechanism equipped with a dump cylinder Cy installed between the vehicle body and a cargo box tiltably mounted on the vehicle body. A hydraulic pump P is driven by a power extraction device that extracts power through a transmission, and the pressure oil supplied from the hydraulic pump P is controlled by a switching valve control device, which causes the dump cylinder cy to expand and contract, causing the cargo box to tilt. It is designed to operate horizontally.

As shown in FIGS. 1 to 4, the switching valve control device includes a switching valve body A in which a plurality of fluid passages are switchable by a spool 2 that is slidable in the axial direction, and one end of the spool 2. The spool 2 is provided with a drive section B that is interlocked with the spool 2 and moves the spool 2 in the axial direction, and a detection section C that detects the position of the spool 2.

In the switching valve main body A, a pump boat 3, a cylinder boat 4, and a tank boat 5 are communicated with a spool insertion hole 1, and a spool slidable in the axial direction is connected to the spool insertion hole 1. 2 is inserted.

The cylinder boat 4 is connected to the rear port of the dump cylinder CyO of the dump truck, and the pump port 3 is connected to the discharge port of the hydraulic pump P. In addition, the oil passage of the pump port 3 and the oil passage of the cylinder port 4 are connected to a check valve C that can flow from the pump port 3 side to the cylinder port 4 side.
They are communicated via k. Furthermore, the tank port 5 is communicated with the tank T.

The spool 2 consists of a large diameter part 6 having approximately the same diameter as the spool insertion hole 1 and a small diameter part 7 having a smaller diameter than the spool insertion hole 1. As the spool 2 moves in the axial direction, the spool insertion hole 1, The fluid passages formed by the pump port 3, cylinder boat 4, and tank port 5 can be switched.

Further, the spool 2 has one end 2a loosely fitted into the housing 11 of the drive section B, and the other end 2b loosely fitted into the housing 21 of the detection section C. Spool 2
A female thread 8 centered on the axis is formed at a predetermined depth in the axial direction on one end 2a, and
Grooves 9, 9 for preventing rotation of the spool 2 are formed on the circumferential surface of the spool 2, each having a predetermined length in the axial direction. These female screws 8
The depth of the slot 9.9 and the length of the slot 9.9 are set by the travel span of the spool 2.

The drive unit B includes a rotating shaft 12 that is linked to one end 2a of the spool 2, and an electric motor 13 that is linked to the rotating shaft 12 via a worm wheel 15 and a worm 16 and rotates the rotating shaft 12 in forward and reverse directions. and an engaging pin 14. which engages with a slot 9°9 formed in one end portion 2a of the spool 2.
It consists of 14.

One end of the rotating shaft 12 passes through the housing 11 and is loosely fitted into the housing 11, and is disposed coaxially with the spool 2. A male thread 12a is formed on the circumferential surface of one end of the rotating shaft 12, and the male thread 12a is screwed into a female thread 8 formed at one end 2a of the spool 2. A worm wheel 15 is also provided at the other end of the rotating shaft 12.
are integrally provided.

The electric motor 13 is rotated by a battery power source of the dump truck, and a worm 16 is integrally provided on a drive shaft 132 of the electric motor 13, and the worm 16 meshes with the worm wheel 15.

The retaining pin 14.14 has a male thread formed on its circumferential surface and a female thread 17 formed through the housing 11.
．． It is screwed into 17. As a result, the engagement pin 14.
The tip end of 14 engages with the slot 9.9 of the spool 2 to prevent the spool 2 from rotating.

Since the rotation of the spool 2 is inhibited, the drive unit B configured in this manner moves the spool 2 in the axial direction by the rotation of the rotating shaft 12 due to the rotation of the electric motor 13. In other words, the direction and amount of movement of the spool 2 can be freely controlled by the electric motor 13.

As mentioned above, the detection unit C detects the position of the spool 2,
That is, the switching state of the fluid passage in the switching valve main body A is detected. This detection part C is connected to the housing 21
Three glue switches 22, 23, and 25 installed in
Each contact 22a, 23a, 25a of these limit switches 22, 23, 25 passes through the housing 21 and is inserted into the housing 21. On the other hand, the other end 2 of the spool 2 loosely fitted into the housing 21
A groove 10 is formed in b, and the limit switch 2
The contacts 22a, 23a, and 25a of 2, 23, and 25 come into contact with the large diameter portion 6 and are in the contact (ON) state, and are in the disconnected (OFF) state when located on the circumferential surface of the groove portion 10.

The width of the groove portion 100 is set by the movement span of the spool 2.

In addition, the three limit switches 22, 23.25 are connected to the contacts 22a, 2 of the limit switches 22.25 when the spool 2 is in the neutral position as shown in FIG.
5a are installed at both ends of the groove 1o, and the contact 23a of the limit switch 23 is located at the center of the groove 10. In this state, all of the limit switches 22, 23, and 25 are turned off. being done.

Table 1 Condition of switching valve main body A and Rimi・Notosui・7chi2
2, 23, and 25 are shown in the disconnected state.

Table 1 Furthermore, FIG. 5 shows the limit switch 2 in Table 1.
2.23.25 contacts 22a, 23a.

25a and the other end 2b of the spool 2 are shown in contact,
In the figure, contacts 22a and 23a are indicated by dotted lines.

25a is in contact with the large diameter portion 6 of the spool 2, and the limit switches 22, 23, and 25 are turned on. Fig. 5(a) shows the state of contact between the two when the switching valve main body A is in the maximum lowered state, and Fig. 5(b) shows the contact state of the switching valve main body A.
Fig. 5 (
5(d) shows the state of contact between the two when the switching valve body A is in the up position, and FIG. Pil indicates the contact state between the two when the switching valve main body A is in the maximum raised state.

In this way, the three limit switches 22, 23° 25
The position of the spool 2 can be detected based on the connected/disconnected state, and the corresponding switching state of the switching valve main body A can be determined.

FIG. 6 shows an electric circuit diagram for controlling the drive of the electric motor 13 and a lamp and a buzzer for informing the operator of the position of the spool moved by the drive of the electric motor 13.

In the figure, SW is an operation switch (operation member) that controls forward and reverse rotation of the electric motor 13;
It is preferable that the device be of a manual operation and automatic return type, which is operated manually and automatically returns to its original state (the state shown in FIG. 6) when it is released. R8-R3 is a relay, R
1m to R31 are normally open relay switches whose opening and closing are controlled by relays R' and -R3, R11+ to R3b are normally closed relay switches whose opening and closing are controlled by relays R8 to R3, 13 is an electric motor, and L is a raised display lamp. , L
2 is a lowering indicator lamp, L is a center indicator lamp, and BZ is a buzzer to notify that the spool has reached the maximum raised and lowered positions.

FIG. 7 shows an operation box 30 installed in the driver's seat of a dump truck. An operation switch SW and display lamps L, -L3 are arranged on the front of this operation box 30, and inside there are various relays. R+, Rz, Rs, buzzer BZ, etc. are stored. The operator can grasp the position of the spool 2, that is, the switching state of the switching valve main body A by means of the display lamps L1 to L3. Further, this operation box 30 can be easily installed within the driver's seat without taking up space.

Next, the operation and effect of the switching valve control device configured as above will be explained.

As shown in FIG. 1, when the operation switch SW is operated to the up side with the spool 2 in the neutral position, the electric motor 13 rotates (for convenience, this direction of rotation is referred to as positive rotation), and the worm 16 and the worm The rotating shaft 12 rotates via the wheel 15. Corresponding to this rotation of the rotating shaft 12, the spool 2 moves rightward in the figure. When the spool 2 moves to the right, the contact 22a of the limit switch 22 comes into contact with the large diameter portion 6 at the other end of the spool 2 and is turned on. As a result, the raised indicator lamp L
, lights up, relay R3 is energized, relay switch R0 is switched from open to closed, relay switch R1b is switched from closed to open, and the correction indicator lamp 3 goes out. Further, when the spool 2 moves to the right, the contact 22a of the limit switch 22 and the contact 23a of the limit switch 23 contact the large diameter portion 6 and are turned on. As a result, relay R2 is energized and relay switch R2m
is switched from open to close, relay switch RZb is switched from close to open, electric motor 13 is stopped, movement of spool 2 is stopped, and buzzer BZ sounds to notify that the maximum raised position has been reached. At this time, the spool 2 is in the position shown in FIG. 3, and the pressure oil supplied from the hydraulic pump P is supplied from the oil passage of the pump port 3 to the oil passage of the cylinder port 4 via the check valve Ck. , dump cylinder cyO
It is supplied to the rear boat and extended. Therefore, the cargo box of this dump truck tilts to the maximum angle.

Furthermore, if the operating switch SW is released while the spool 2 is being switched from the neutral position to the maximum raised position, the operating switch SW returns to the non-contact position shown in FIG. 6, the electric motor 13 stops, and the The spool 2 also stops at a position in the middle of switching. At this time, the pump port 3 is not completely closed by the large diameter portion 6 of the spool 2, and therefore some of the pressure oil supplied to the pump port 3 from the hydraulic pump P also flows to the tank port 5 side. The amount of pressurized oil supplied from the pump port 3 to the cylinder port 4 is reduced by the amount that is partially detoured to the tank port 5.

Therefore, the dump cylinder cy expands by an amount corresponding to the amount of pressure oil supplied from the pump port 3 to the cylinder port 4, and the cargo box tilts more slowly than when the spool 2 is at the maximum raised position. In this way, by operating the operation switch SW and stopping the spool 2 at any position during switching, the amount of pressurized oil sent from the pump port 3 side to the cylinder port 4 side is adjusted and the dump cylinder cy is extended. The movement can be controlled and the tilting speed of the cargo box can be adjusted arbitrarily.

Next, when the operation switch SW is turned down with the spool 2 in the neutral position, the electric motor 13 rotates in the opposite direction (referred to as reverse rotation) with respect to the forward rotation when the operation switch SW is turned up. ), and the rotating shaft 12 also rotates in the opposite direction to the above via the worm 16 and the worm wheel 15.

Corresponding to this reverse rotation, the spool 2 moves to the left in the figure. When the spool 2 moves to the left, the contact 25a of the limit switch 25 comes into contact with the large diameter portion 6 of the other end 2b of the spool 2 and is turned on. by this,
As the lowering indicator lamp L2 lights up, the relay R3 is energized, the relay switch Rffa switches from open to closed, the relay switch R3b switches from closed to open, and the neutral indicator lamp L goes out. Furthermore, when the spool 2 moves to the left, the contact 25a of the limit switch 25 and the contact 23a of the limit switch 23 contact the large diameter portion 6 and are turned on. As a result, relay R2 is energized and relay switch R2m is changed from open to closed.
2b switches from closed to open, the electric motor 13 stops and the movement of the spool 2 stops, and a buzzer BZ sounds to notify that the maximum lowered position has been reached. At this time, the spool 2 is in the position shown in FIG.
is returned to the tank via Therefore, dump cylinder cy
degenerates, and the dump truck's cargo box falls to a horizontal position.

Furthermore, if the operation switch SW is released while the spool 2 is being switched from the mid-normal position to the maximum lowered position, the operation switch SW returns to the non-contact position shown in FIG. 6, the electric motor 13 stops, and the electric motor 13 stops. The spool 2 also stops at a position in the middle of switching.

At this time, the switching valve main body A is not opened when the cylinder boat 4 is in the maximum lowered state, and it takes a while for the pressure oil supplied to the dump cylinder cy to return from the cylinder port 4 to the tank via the tank boat 5. is slower than when it is in the maximum lowered state. Therefore, the dump cylinder cy is slowly retracted, and the dump truck's cargo box is laid down more slowly than when it is in the maximum lowered state. In this way, by operating the operation switch SW and stopping the spool 2 at any position during switching, the pressure oil returned to the tank from the cylinder port 4 is adjusted to control the retracting operation of the dump cylinder cy, and the loading box You can adjust the speed at which it falls prone. Further, since the electric motor 13 is driven only by battery power, the position of the spool 2 can be moved even after the engine is stopped. Therefore, even when the engine is stopped, the cargo box can be laid down, and the speed at which the cargo box is laid down can also be adjusted.

The switching valve control device constructed as described above is easy to change from a manually operated type, since the valve part can be used as is, and the piping does not need to be changed, and the installation is easy. It's almost the same as the one.

(Effects of the Invention) As described above, according to the present invention, the spool can be stopped at any arbitrary position, that is, even in the middle of switching, and the spool can be inched. In addition, there is less shock during switching, which helps protect equipment.

[Brief explanation of the drawing]

1 to 7 show a switching valve control device in a hydraulically operated device according to the present invention, FIG. 1 is a sectional view showing the switching valve control device with the hydraulic valve main body in a neutral state, and FIG. , a cross-sectional view showing a worm and a worm wheel, 3rd
The figure is a sectional view showing the switching valve control device with the switching valve main body in the maximum raised state, Figure 4 is a sectional view showing the switching valve control device with the switching valve main body in the maximum lowered state, and Figure 5 is the switching valve main body. FIG. 6 is an electric circuit diagram, and FIG. 7 is a perspective view of an operation box for operating this switching valve control device. 2... Spool 13... Electric motor A...
Switching valve body part B...Drive part C...Detection part
SW...Operating switch (operating member) Fig. 2 Fig. 5 Fig. 6 Fig. 7

Claims (1)

[Claims] 1) A switching valve control device that is disposed between a hydraulically operated device and a hydraulic pump driven by a power extraction device that extracts power from a power source, and controls pressure oil from the hydraulic pump. The switching valve control device includes a switching valve main body in which a plurality of fluid passages can be switched by a spool that is slidable in the axial direction, and a switching valve body that is interlocked with one end of the spool to move the spool in the axial direction. a drive unit for moving the spool, and a detection unit for detecting the position of the spool, and the drive unit has an electric motor whose forward and reverse rotation can be controlled by an operating member, and the rotation of the electric motor causes the spool to move. 1. A switching valve control device for hydraulically operated equipment, characterized in that the spool is moved in the axial direction and the spool can be stopped at any position by arbitrarily stopping the rotation of the electric motor. 2) The detection unit is configured with at least three limit switches that are switched and controlled by the spool, and detects the position of the spool based on the connection/disconnection states of these limit switches. A switching valve control device for a hydraulic machine according to paragraph 1. 3) The switching valve control device for hydraulically operated equipment according to claims 1 and 2, wherein the information detected by the detection section is displayed on a display means.