JP2002144943A - Cylinder synchronous device of gate lifter - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a cylinder synchronous device of a gate lifter capable of simply correcting a gate positioned at an appropriate descended position to a horizontal state by a simple mechanism. SOLUTION: In this gate lifter, a rod side chamber 3Lc of a first hydraulic cylinder 3L is connected to a driving source 41 via a first pipe 42 and an opposite rod side chamber 3Lb is connected to a rod side chamber 3Rc of a second hydraulic cylinder 3R via a second pipe 43. An opposite rod side chamber 3Rb of the second hydraulic cylinder 3R is released to the atmosphere or is connected to a reservoir 41d via a third pipe 44. The gate is ascended/descended along a strut by telescoping the first and second hydraulic cylinders 3L, 3R while synchronizing them. The first pipe 42 and the second pipe 43 are communicated by a first communication pipe 45a provided with a first synchronous valve 45c. A midway part of the first communication pipe 45a being the second piping 43 side as compared with the first synchronous valve 45c and the reservoir 41d are communicated by a second communication pipe 45b provided with a second synchronous valve 45d.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a gate lifter cylinder synchronizing device for raising and lowering a gate by a pair of hydraulic cylinders, and more particularly, to easily adjust the displacement of one or the other hydraulic cylinder in the vertical direction at an appropriate lowered position. Relating to measures that can be corrected.

[0002]

2. Description of the Related Art In general, a gate at the rear end of a truck vehicle is raised and lowered by a gate lifter which supplies and discharges hydraulic oil from a hydraulic pump to a pair of cylinders to extend and contract a piston rod of each cylinder. . In such a gate lifter, the piston rods of each cylinder are attached to both left and right ends of the gate, so a cylinder tuning device that synchronizes the amount of expansion and contraction of the piston rod of each cylinder is required to keep the gate horizontal. It is considered indispensable.

As shown in FIG. 4, this cylinder tuning device is configured such that a rod side chamber A1a of one cylinder A1 (left side in FIG. 4) is connected to a pump unit A2 by a first pipe A3.
, And the opposite rod side chamber A1b of one cylinder A1 and the other cylinder A4 (right side in FIG. 4).
Is connected to the rod side chamber A4a through a second pipe A5,
Conventionally, check valves A6, A6 are provided in through holes A1d, A4d, which penetrate the pistons A1c, A4c of the cylinders A1, A4 in the direction of expansion and contraction, respectively.

[0004] The pump unit A2 includes a motor A2a.
And the reservoir tank A2b are integrated,
A gear pump A2c is interposed between the two A2a and A2b. Then, the cylinder tuning apparatus A connects each check valve A6 to the opposite rod side chamber A1 of each cylinder A1, A4 at the upper limit position of the gate A7 substantially flush with the deck of the packing box.
b, A4b are brought into contact with the end faces to be opened, and the opposite rod side chambers A1b, A4b of the cylinders A1, A4 communicate with the rod side chambers A1a, A4a, respectively. This allows
The pressure of the pressurized oil is adjusted by increasing or decreasing the amount of oil in the non-rod side chambers A1b, A4b and the rod side chambers A1a, A4a of each cylinder A1, A4, and the expansion and contraction amounts of the piston rods A1e, A4e of each cylinder A1, A4 are adjusted. Like that.

[0005]

However, in the conventional cylinder tuning apparatus A, the check valves A6 are provided in the through holes A1d and A4d of the pistons A1c and A4c of the cylinders A1 and A4, respectively.
The structure of 4c is complicated, and the cost is high.

In addition, since the through holes A1d and A4d are opened in the pistons A1c and A4c of the cylinders A1 and A4, the opposite rod side chambers A1b and A1b of the cylinders A1 and A4 are provided.
The working fluid such as pressure oil may leak through the through holes A1d and A4d between the A4b and the rod side chambers A1a and A4a, and there is a fear that the working fluid may leak internally.

SUMMARY OF THE INVENTION The present invention has been made in view of the foregoing, and an object of the present invention is to provide a gate lifter which can easily correct a gate at an appropriate lowered position to a horizontal state by a simple mechanism. It is to provide a cylinder tuning device.

[0008]

According to a first aspect of the present invention, there is provided a gate lifter cylinder tuning apparatus comprising: a pressure receiving area on a side opposite a rod side chamber of a piston of a first hydraulic cylinder; The pressure receiving area is the same, the rod side chamber of the first hydraulic cylinder is connected to the drive source via the first pipe, and the opposite rod side chamber of the first hydraulic cylinder is connected to the rod side chamber of the second hydraulic cylinder by the second hydraulic cylinder.
The second hydraulic cylinder is connected to a reservoir tank via a third pipe, and the working chamber is connected to a reservoir tank via a third pipe. In the gate lifter which supplies and discharges and expands and contracts the piston rods of the respective cylinders while synchronizing them, the gate connected to the piston rods is moved up and down along a pair of right and left columns. The first with the first tuning valve
The first communication pipe is communicated with the communication pipe, and an intermediate portion of the first communication pipe closer to the second pipe than the first tuning valve is communicated with the reservoir tank by the second communication pipe having the second tuning valve. .

According to a second aspect of the present invention, in the gate lifter cylinder tuning apparatus, the first tuning valve and the second tuning valve are solenoid valves.

According to a third aspect of the present invention, in the gate lifter cylinder tuning apparatus, a detection device for detecting a height position of the left and right sides of the gate is provided on the support, and the first position is detected based on the detection of the detection device. The first tuning valve and the second tuning valve are controlled to open and close to synchronize the expansion and contraction amounts of the piston rods of the first hydraulic cylinder and the second hydraulic cylinder.

According to a fourth aspect of the present invention, in the gate lifter cylinder tuning apparatus, the pressure receiving area of the piston of the first hydraulic cylinder on the side opposite to the rod side chamber is equal to the pressure receiving area of the piston of the second hydraulic cylinder on the side of the rod side chamber. The rod side chamber of the first hydraulic cylinder is connected to the drive source via the first pipe, and the opposite rod side chamber of the first hydraulic cylinder is connected to the rod side chamber of the second hydraulic cylinder via the second pipe, Further, the opposite rod side chamber of the second hydraulic cylinder is open to the atmosphere or is connected to a reservoir tank via a third pipe, and supplies and discharges a working fluid from a driving source to the first hydraulic cylinder, thereby controlling each cylinder. A gate that moves the gates connected to these piston rods up and down along a pair of left and right columns by extending and contracting the piston rods while synchronizing them. In the lid, wherein the first hydraulic cylinder and a hydraulic circuit for stretching operates the second hydraulic cylinder, the predetermined time period when the main switch is OFF 1
A circuit for communicating the rod side chamber of the hydraulic cylinder with the reservoir tank and lowering the gate slightly is provided.

[0012]

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

FIG. 1 shows the rear of a truck provided with the gate lifter cylinder tuning apparatus of the present invention. The truck T has a packing box Tb at the rear of the vehicle body Ta. A gate lifter 1 is provided at the rear end of the packing box Tb. The gate lifter 1 is connected to the gate T of the track T.
By raising and lowering c in the vertical direction along the column 2 (described later), it is provided for facilitating the loading and unloading work of loading and unloading the unshown luggage into the packing box Tb.

The gate lifter 1 comprises a pair of right and left columns 2
(Only one is shown in FIG. 1) and a pair of first and second left and right
It includes hydraulic cylinders 3L, 3R and a cylinder tuning device 4 (shown in FIG. 2).

Each of the columns 2 extends vertically upward from the deck surface Td at both left and right positions of the rear end of the packing box Tb. A slider 21 is provided in each of the columns 2 so as to be vertically movable along the column 2. At the lower end of each slider 21, a support bracket 22 projecting rearward from the column 2 is provided. The support bracket 22 has a base end portion of the gate Tc (FIG. 1).
The front end is supported rotatably about a horizontal axis (not shown). In this case, the gate Tc pivots around the horizontal axis with respect to each support bracket 22, so that the gate Tc stands upright along each column 2, and falls down substantially horizontally (position shown in FIG. 1). The posture is mutually changed.

Rollers 21a, 21a are rotatably supported on the upper end and the middle of each slider 21, and the respective sliders 21a allow the slider 21 to slide smoothly in the up and down direction within the column 2. ing.

The first and second hydraulic cylinders 3L, 3R are:
Each of the columns 2 is provided so as to extend in the vertical direction substantially in parallel with each column 2. As shown in FIG. 2, each hydraulic cylinder 3L,
3R is composed of the upper and lower rod side chambers 3Lb and 3Rb and the lower rod side chambers 3Lc and 3R by the pistons 3La and 3Ra.
The front ends of the support brackets 22 are connected to distal ends (lower ends) of the piston rods 3Ld and 3Rd, respectively, which are defined below the pistons 3La and 3Ra.

In this case, the first hydraulic cylinder 3L and the second hydraulic cylinder 3R are connected to the side of the piston 3La of the first hydraulic cylinder 3L opposite the rod side chamber 3Lb (the upper surface in FIG. 2).
Pressure receiving area and the piston 3Ra of the second hydraulic cylinder 3R
In order to match the pressure receiving area of the side surface of the rod side chamber 3Rc (the lower surface in FIG. 2), the rods are formed to have different diameters.

The gate Tc supplies pressure oil to the rod-side chamber 3Lc of the first hydraulic cylinder 3L as described later, and the slider 21 via the support bracket 22 at the time of contraction to contract each of the piston rods 3Ld and 3Rd. Is raised, so that it is positioned at the upper limit position (the solid line position shown in FIG. 1) which is substantially flush with the deck surface Td of the packing box Tb. On the other hand, the gate Tc discharges pressurized oil from the rod side chamber 3Lc of the first hydraulic cylinder 3L and lowers the slider 21 via the support bracket 22 when the piston rods 3Ld and 3Rd are extended to extend to the ground G. It is positioned at a descending position where it touches the ground (a position indicated by a two-dot chain line in FIG. 1).

The cylinder tuning device 4 corrects the displacement of the piston rods 3Ld, 3Rd of the left and right hydraulic cylinders 3L, 3R when the displacement has occurred, and tunes the displacement of the piston rods 3Ld, 3Rd. And a pump unit 41 as a drive source, first to third pipes 42 to 44, and a tuning pipe 45.

As shown in FIG. 2, the pump unit 41 includes a gear pump 41b driven by a motor 41a,
A control valve 41c for controlling the elevation of the gate Tc and a reservoir tank 41d are provided as main parts.

The gear pump 41b has a suction port connected to a reservoir tank 41d through a suction pipe 41e, and one end of the first pipe 42 connected to a discharge port.

The control valve 41c is a two-position switching type solenoid valve that can be switched between an upper position and a lower position in FIG. 2 by exciting and demagnetizing the solenoid SOL3 by operating a gate lift switch (not shown). It is interposed in a discharge pipe 41f that communicates with the middle part and the reservoir tank 41d.

Further, a flow regulating valve 41h is interposed in the discharge pipe 41f closer to the reservoir tank 41d than the control valve 41c. The flow rate adjusting valve 41h adjusts the flow rate of the pressure oil flowing from the first pipe 42 to the reservoir tank 41d to a predetermined amount, so that the descending speed of the gate Tc becomes constant.

The first pipe 42 has one end connected to the discharge port of the gear pump 41d as described above, and the other end connected to the rod side chamber 3Lc of the first hydraulic cylinder 3L. A first gear pump 41d closer to the gear pump 41d than the communicating portion of the discharge pipe 41f.
A check valve 41i is interposed in the pipe 42.
i prevents the backflow of the pressure oil to the gear pump 41d side.

The second pipe 43 has one end connected to the opposite rod side chamber 3Lb of the first hydraulic cylinder 3L and the other end connected to the rod side chamber 3Rc of the second hydraulic cylinder 3R.

The third pipe 44 has one end connected to the opposite rod side chamber 3Rb of the second hydraulic cylinder 3R and the other end connected to the reservoir tank 41d.

The tuning pipe 45 has a first communication pipe 45a communicating with a middle part of the first pipe 42 on the first hydraulic cylinder 3L side with respect to the communication part of the discharge pipe 41f and a middle part of the second pipe 42. And a second communication pipe 45b communicating with the middle part of the first communication pipe 45a and the reservoir tank 41d, and a first communication pipe 45a closer to the first pipe 42 than the communication part between the second communication pipe 45b. It comprises a first tuning valve 45c provided and a second tuning valve 45d provided in the second communication pipe 45b.

The first tuning valve 45c is switched between an upper position and a lower position in FIG. 2 by exciting and demagnetizing the solenoid SOL1 by operating a tuning switch (not shown).
This is a position switching type solenoid valve. The first tuning valve 45c opens the first communication pipe 45a at the upper position and closes the first communication pipe 45a at the lower position.

The second tuning valve 45d is of a two-position switching type that can be switched between an upper position and a lower position in FIG. 2 by exciting and demagnetizing the solenoid SOL2 by operating a tuning switch (not shown), similarly to the first tuning valve 45c. A solenoid valve that opens the second communication pipe 45b at the upper position and closes the second communication pipe 45b at the lower position.

Next, when the gate is lifted and lowered by the gate lifter cylinder tuning device having the above-described structure, and when the gate is tilted to the left or right from a horizontal state, the gate is adjusted by adjusting the tilt. A description will be given of a tuning operation for bringing the camera into a horizontal state.

First, the first and second tuning valves 45c and 45d take the lower position, and the first and second communication pipes 45a and 45d respectively.
When the control valve 41c is switched to the raised position by the gate raising / lowering switch in a state in which the motor 4 is closed, the motor 4
The gear pump 41b is driven by 1a to supply pressure oil to the first pipe 42. Thereby, the first hydraulic cylinder 3L
The pressure oil is supplied to the rod side chamber 3Lc, and the piston rod 3Ld of the first hydraulic cylinder 3L contracts. At the same time, from the opposite rod side chamber 3Lb of the first hydraulic cylinder 3L,
The same amount of pressure oil as the pressure oil supplied to the rod side chamber 3Lc of the first hydraulic cylinder 3L is supplied to the rod side chamber 3Rc of the second hydraulic cylinder 3R through the second pipe 43, and the pressure receiving areas are made equal as described above. Therefore, the piston rod 3Rd of the second hydraulic cylinder 3R is retracted by the same length as the piston rod 3Ld. In this way, the left and right first and second hydraulic cylinders 3L, 3R are synchronized, so that the gate Tc ascends to the ascending position while maintaining the horizontal position.

On the other hand, the control valve 4 is controlled by a gate lift switch.
When 1c is switched to the lowered position, the pressure oil is returned from the rod side chamber 3Lc of the first hydraulic cylinder 3L to the reservoir tank 41d through the first pipe 42 and the discharge pipe 41f by the weight of the gate Tc. Thereby, the first hydraulic cylinder 3L
The piston rod 3Ld extends. At the same time as the first
In the opposite rod side chamber 3Lb of the hydraulic cylinder 3L, the same amount of pressure oil as the pressure oil returned from the rod side chamber 3Lc of the first hydraulic cylinder 3L is supplied to the rod side chamber 3Rc of the second hydraulic cylinder 3R.
Through the second pipe 43, the piston rod 3Rd of the second hydraulic cylinder 3R extends the same length as the piston rod 3Ld. In this way, the left and right first and second hydraulic cylinders 3L and 3R are synchronized, and the gate Tc descends to the descending position while maintaining the horizontal position.

Next, the gate Tc which moves up and down as described above
Is tilted to the left or right due to, for example, leakage of pressure oil from the rod side chamber 3Lc of the first hydraulic cylinder 3L to the opposite rod side chamber 3Lb, and the left and right first and second hydraulic cylinders 3L by the cylinder tuning device 4. Gate T by adjusting the amount of expansion and contraction of piston rods 3Ld and 3Rd of 3R
A procedure for correcting c to a horizontal state will be described.

When the operator finds that the gate Tc is tilted to the left or right, the operator first stops the gate Tc at an appropriate position on the way down. That is, the control valve 41c
Is switched from the upper position to the lower position to stop the gate Tc. At this time, the drive of the gear pump 41d is stopped.

If, for example, the first hydraulic cylinder 3L (left side) shifts in the downward direction and the left side of the gate Tc is inclined downward, only the second tuning valve 45d is moved to the upper position by the tuning switch. Switch to. Thereby, the pressure oil in the rod side chamber 3Rc of the second hydraulic cylinder 3R is discharged to the reservoir tank 41d through the second pipe 43, the first communication pipe 45a, and the second communication pipe 45b. Therefore, the piston rod 3Rd of the second hydraulic cylinder 3R is equivalent to the pressure oil.
Extend, and the right side of the gate Tc descends. When the gate Tc becomes horizontal due to the lowering of the right side of the gate Tc, the operator stops the lowering of the right side of the gate Tc by switching the second tuning valve 45d to the lower position by the tuning switch. As a result, the displacement in the descending direction on the first hydraulic cylinder 3L side (left side) is corrected, and the gate Tc is brought into a horizontal state.

On the other hand, if the right side of the gate Tc is tilted downward due to a downward displacement on the second hydraulic cylinder 3R side (left side), only the first tuning valve 45c is moved to the upper position by the tuning switch. Switch. As a result, the pressure oil in the rod side chamber 3Lc of the first hydraulic cylinder 3L flows through the first pipe 42 and the first communication pipe 45a to the second pipe 43, and the piston rod 3Ld of the first hydraulic cylinder 3L corresponds to the pressure oil.
Extend and the left side of the gate Tc descends. When the gate Tc becomes horizontal due to the lowering of the left side of the gate Tc, the operator stops the lowering of the left side of the gate Tc by switching the first tuning valve 45c to the lower position by the tuning switch. As a result, the displacement in the descending direction on the second hydraulic cylinder 3R side (right side) is corrected, and the gate Tc is brought into a horizontal state.

When correcting the inclination of the gate Tc, a tuning weight may be placed on the gate Tc as necessary.

With the simple configuration of the first tuning valve 45c and the second tuning valve 45d, the inclination of the gate Tc can be easily corrected, and the workability is good.

In the above-described embodiment, the solenoid valve is used as an example of the first tuning valve 45c and the second tuning valve 45d. However, a manual valve is used to open and close the valve. You may do it.

The non-rod side chamber 3Rb of the second hydraulic cylinder 3R is connected to the reservoir tank 41 through the third pipe 44.
Although it communicates with d, the non-rod side chamber 3Rb of the second hydraulic cylinder 3R may be opened to the atmosphere.

FIG. 3 shows an electric circuit (operation circuit) for automatically controlling the above-described cylinder tuning device 4.

This circuit is a circuit for raising and lowering the gate Tc, and has two limit switches L as detection devices.
Two first and second relay contact groups 51 and 52 that are connected and disconnected based on detection by S1 and LS2, and a tuning switch 53
It has.

The limit switch LS1 is provided, for example, at the lower end of the right column 2 as shown in FIG. 1, and when the right bracket 22 comes into contact when the gate Tc descends, the limit switch LS1 is placed on the right side of the gate Tc. It detects that the part has reached its height position.

The limit switch LS2 is connected to the left support 2
The lower end of the gate Tc is provided in the same manner as the limit switch LS1, and when the gate Tc descends, the left bracket 22 abuts so that the left side of the gate Tc has the same height as the right side of the gate Tc. Detect that the position has been reached.

The first relay contact group 51 is provided with a first b contact 51 communicating with the solenoid SOL3 of the control valve 41c.
a, a contact 51b communicating with the solenoid SOL1 of the first tuning valve 45c, and a solenoid SOL of the second tuning valve 45d.
2 and a second b-contact 51c communicating with the second b-contact 51c.

The second relay contact group 52 includes a first b contact 52a arranged in series with the first b contact 51a, and a second b contact 52b arranged in series with the a contact 51b.
And an a contact 52c arranged in series with the second b contact 51c.

In FIG. 3, reference numeral 54 denotes a main switch, 55 denotes a gate elevating switch provided on the vehicle, 56 denotes a remote-controlled gate elevating switch, and 57 denotes a safety switch. Either of the lifting switches 55 and 56, the raising switch 5
By operating the switches 5a and 56a or the down switches 55b and 56b, the elevation of the gate Tc is operated.

More specifically, when the raising switch 55a of the gate raising / lowering switch 55 is turned on, the motor 41a is energized while the control valve 41c is in the lower position.
Is driven, and the pressure oil is supplied from the gear pump 41b to the first hydraulic cylinder 3L as described above, so that the gate Tc
Rises. On the other hand, when the lowering switch 55b of the gate raising / lowering switch 55 is turned on, the control valve 41c is switched to the upper position, the power supply to the motor 41a is cut off, and the driving of the motor 41a is stopped. When the pressure oil is returned from the cylinder 3L to the reservoir tank 41d, the gate Tc is lowered.

When the ascending gate Tc is tilted to the left or right, the gate Tc is switched to the limit switch L.
By turning on the tuning switch 53 in a state where it is arranged at a position higher than S1 and LS2, the inclination of the gate Tc is automatically corrected as follows.

First, when the tuning switch 53 is turned on to excite the solenoid SOL3 of the control valve 41c, the control valve 41c is switched to the upper position, whereby the gate Tc is lowered.

If, for example, a downward shift occurs on the first hydraulic cylinder 3L side (left side) and the left side of the gate Tc is inclined downward, first, the left limit switch LS2 is moved to the gate Tc. Touch Thereby, each contact 52a, 52b, 52c of the relay contact group 52 opens and closes,
By this opening and closing, the solenoid SOL3 is demagnetized, the control valve 41c is switched to the lower position, and the lowering of the gate Tc is stopped, and the solenoid SOL2 is excited to switch the second tuning valve 45d to the upper position. Therefore, the pressure oil in the rod side chamber 3Rc of the second hydraulic cylinder 3R is discharged to the reservoir tank 41d through the second pipe 43, the first communication pipe 45a, and the second communication pipe 45b. As a result, the piston rod 3Rd of the second hydraulic cylinder 3R extends by the amount of the pressurized oil, and the right side of the gate Tc descends.
Is in contact with the bracket 22 on the right side of the gate Tc, the respective contacts 51a, 51b, 51c of the relay switch group 51 are opened and closed, so that the solenoid LS2 is demagnetized and the second tuning valve 45d is switched to the lower position. Stop descent on the right side of. This corrects the downward displacement of the gate Tc on the first hydraulic cylinder 3L side (left side),
The gate Tc becomes horizontal.

On the other hand, for example, when the right side of the gate Tc is inclined downward due to a downward displacement on the second hydraulic cylinder 3R side (right side), first, the right limit switch LS1 is moved to the gate Tc. Touch Thereby, each contact 51a, 51b, 51c of the relay contact group 51 opens and closes,
By this opening and closing, the solenoid SOL3 is demagnetized, the control valve 41c is switched to the lower position, the lowering of the gate Tc is stopped, and the solenoid SOL1 is excited to switch the first tuning valve 45a to the upper position. Therefore, the pressure oil in the rod side chamber 3Lc of the first hydraulic cylinder 3L flows through the first pipe 42 and the first communication pipe 45a to the second pipe side. As a result, the piston rod 3Ld of the first hydraulic cylinder 3L extends by the amount of the pressure oil which flows, and the gate Tc
When the limit switch LS2 comes into contact with the bracket 22 on the left side of the gate Tc due to the lowering of the left side of the gate Tc, each contact 52 of the relay contact group 52
a, 52b, and 52c open and close to open the solenoid SO.
L1 is demagnetized and the first tuning valve 45a is switched to the lower position, and the lowering of the left side of the gate Tc is stopped. As a result,
The displacement in the descending direction on the second hydraulic cylinder 3R side (left side) is corrected, and the gate Tc is in a horizontal state.

When correcting the inclination of the gate Tc, a tuning weight may be placed on the gate Tc as necessary.

By operating the tuning switch 53 in this manner, the inclination of the gate Tc can be automatically and easily corrected.

Further, in the above-described electric circuit, when the main switch 54 is turned off, the solenoid SOL3 is excited for a predetermined time to switch the control valve 41c to the upper position.
A circuit 58 for reducing the pressure of the pressure oil in the rod side chamber 3Lc of the first hydraulic cylinder 3L is provided.

This circuit 58 comprises a timer relay 58a and a timer contact 58b, and turns on the main switch 54.
As a result, the timer relay 58a is energized to close the timer contact 58b, and the main switch 5
When the timer relay 58a is de-energized by turning off the timer relay 58a, the timer contact 58b is turned on for a predetermined time (for example, about 0.3 mm).
(Approximately 5 seconds to 1 second). Thus, when the main switch 54 is turned off, the timer relay 58a is closed, so that the solenoid SOL3 of the control valve 41c is excited for a predetermined time. As a result, the control valve 41c is switched to the upper position for a predetermined time, and the rod-side chamber 3 of the first hydraulic cylinder 3L is moved.
The pressure oil of Lc is slightly returned to the reservoir tank 41d.

As a result, when the gate Tc reaches the raised position, the rod-side chamber 3L of the first hydraulic cylinder 3L
The pressure of the pressure oil sealed in c can be reduced. As a result, the pressure oil in the rod side chamber 3Lc of the first hydraulic cylinder 3L can be prevented from leaking from the rod side chamber 3Lc to the side opposite to the rod side chamber 3Lb, and the gate can be prevented from tilting due to this leak. Tuning work can be reduced.

[0059]

As described above, according to the gate lifter cylinder tuning apparatus of the present invention, the right and left inclinations of the gate can be easily corrected to the horizontal state by the simple configuration of the first tuning valve and the second tuning valve. can do. In addition, by opening and closing the first tuning valve and the second tuning valve based on the detection device, the right and left inclination of the gate can be automatically corrected to be horizontal, and the workability can be improved.

Further, at the end of the operation of turning off the main switch, the pressure of the pressure oil sealed in the rod side chamber of the first hydraulic cylinder when the gate reaches the raised position can be reduced. This prevents the pressure oil in the rod side chamber of the first hydraulic cylinder from leaking from the rod side chamber to the side opposite to the rod side chamber, thereby preventing the gate from being tilted due to the leak, thereby reducing the tuning operation and workability. Can be improved.

[Brief description of the drawings]

FIG. 1 is a sectional view of the vicinity of a rear portion of a track provided with a gate lifter cylinder tuning device of the present invention.

FIG. 2 is a hydraulic piping system diagram of the cylinder tuning device.

FIG. 3 is an electric circuit diagram of the cylinder tuning device.

FIG. 4 is a hydraulic piping system diagram of a cylinder tuning device according to a conventional example.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Gate lifter 2 Prop 3L 1st hydraulic cylinder 3Lb Non-rod side chamber 3Lc Rod side chamber 3Ld Piston rod 3R 2nd hydraulic cylinder 3Rc Rod side chamber 3Rd Piston rod 4 Cylinder tuning device 41 Pump unit (drive source) 41d Reservoir tank 42 First pipe 43 First 2 pipe 44 3rd pipe 45 Tuning pipe 45a 1st communicating pipe 45b 2nd communicating pipe 45c 1st tuning valve 45d 2nd tuning valve 53 Tuning switch 54 Main switch 58 Circuit LS1 Limit switch LS2 Limit switch

Claims (4)

[Claims] The pressure receiving area on the side of the piston of the first hydraulic cylinder opposite to the rod side is equal to the pressure receiving area of the side of the rod side chamber of the piston of the second hydraulic cylinder, and the rod side chamber of the first hydraulic cylinder is driven by the drive source. Is connected to the rod side chamber of the first hydraulic cylinder via a second pipe, and the opposite rod side chamber of the second hydraulic cylinder is connected to the atmosphere. Open or connected to a reservoir tank via a third pipe, the hydraulic fluid is supplied and discharged from the drive source to the first hydraulic cylinder, and the piston rod of each cylinder is expanded and contracted while being tuned. In a gate lifter for raising and lowering a gate connected to a piston rod along a pair of right and left columns, the first pipe and the second pipe are the same as each other. With communicated by the first communication pipe having a valve, than the first tuning valve second
A cylinder synchronizing device for a gate lifter, wherein a middle part of the first communication pipe on the pipe side and the reservoir tank are communicated by a second communication pipe having a second tuning valve. 2. The gate lifter cylinder tuning device according to claim 1, wherein the first tuning valve and the second tuning valve are solenoid valves. 3. A detection device for detecting the height position of the left and right sides of the gate is provided on the support, and the first and second tuned valves are opened and closed based on the detection of the detection device. 3. The gate lifter cylinder tuning device according to claim 2, wherein the amount of expansion and contraction of each piston rod of the first hydraulic cylinder and the second hydraulic cylinder is adjusted. 4. The pressure receiving area on the side of the piston of the first hydraulic cylinder opposite to the rod side chamber is equal to the pressure receiving area of the side of the rod side chamber of the piston of the second hydraulic cylinder, and the rod side chamber of the first hydraulic cylinder is driven by the drive source. Is connected to the rod side chamber of the first hydraulic cylinder via a second pipe, and the opposite rod side chamber of the second hydraulic cylinder is connected to the atmosphere. Open or connected to a reservoir tank via a third pipe, the hydraulic fluid is supplied and discharged from the drive source to the first hydraulic cylinder, and the piston rod of each cylinder is expanded and contracted while being tuned. A gate lifter for raising and lowering a gate connected to a piston rod along a pair of right and left columns, wherein the first hydraulic cylinder and the second hydraulic cylinder The operating circuit for extending and retracting the damper is characterized in that a circuit for communicating the rod side chamber of the first hydraulic cylinder with the reservoir tank for a predetermined time when the main switch is turned off and slightly lowering the gate is provided. Gate lifter cylinder tuning device.