JPH04315670A - Hydraulic high raising parking device - Google Patents

Abstract

PURPOSE:To prevent the tilting of a pallet by synchronizing the actions of two cylinders with only the structure of a hydraulic circuit regardless of the unbalance of the load applied to the pallet. CONSTITUTION:The head side chamber 11 of the first hydraulic cylinder 1 is connected to a pressure line R, the head side chamber 21 of the second hydraulic cylinder 2 is connected to a tank T4, and rod side chambers 12, 22 are connected to a communicating path 4. A fixed pulley 51 reversing the action of the rod 20 of the second hydraulic cylinder 2 is provided, the oil quantity exchanged between the rod side chambers 12, 22 is made equal at the time of an ascent when pressure oil is guided into the head side chamber 11 of the first hydraulic cylinder 1 and at the time of a descent when the pressure oil of the rod side chamber 11 is released to the tank T4, and action strokes of the rods 10, 20 are made equal.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a hydraulic multilevel parking system in which a pallet for mounting on a vehicle is raised and lowered using two hydraulic cylinders.

0002

[Prior Art] Conventionally, this type of hydraulic multi-level parking system has two hydraulic cylinders on the left and right sides of the pallet, and in order to prevent the pallet from tilting by synchronizing the operation of these two hydraulic cylinders, For example, as known from Japanese Utility Model Application Publication No. 2-125155, a distribution branch valve is interposed in one pressure line for supplying and discharging pressure oil, and a distribution path is branched to evenly distribute the flow rate to each cylinder. , each branch path is connected to each cylinder so that the forward and backward strokes of each cylinder are made to match.

0003

[Problem to be Solved by the Invention] However, in the above system, the flow rates of the two distribution channels are equalized using the distribution flow valve, and the two cylinders are synchronized. Regardless of the case where the load acting on each cylinder is equal, if there is a difference in the load acting on each cylinder due to a shift in the parking position of the vehicle loaded on the pallet, a difference will occur in the pressure in each distribution path, and the distribution will be affected. There is a problem in that there is a difference in the flow rate distributed to each distribution path via the flow divider valve, and a difference in the stroke of each cylinder, which ultimately causes the pallet to tilt, making it impossible to achieve accurate synchronization. .

On the other hand, since accurate synchronization cannot be achieved with only a hydraulic circuit configuration, it may be possible to use a mechanical synchronization mechanism such as providing a guide roller on the pallet and guiding it onto a guide rail. In this case, the problem arises that the structure becomes complicated.

SUMMARY OF THE INVENTION An object of the present invention is to provide a hydraulic multilevel parking system that has a simple structure, can synchronize two cylinders well, and can prevent pallets from tilting.

[0006]

[Means for Solving the Problems] Therefore, in the present invention, in order to achieve the above object, as shown in FIG. In a hydraulic multilevel parking system that is raised and lowered by a lifting device, the head side chamber 11 of the first hydraulic cylinder 1 is connected to a pressure line whose connection is switched between a discharge line extending from a hydraulic pump and a tank line leading to a tank. At the same time, the head side chamber 21 of the second hydraulic cylinder 2 is connected to the tank line leading to the tank, while each rod side chamber 12 of the first and second hydraulic cylinders 1 and 2 is connected to the tank line leading to the tank.
, 22 are connected to each other via a communication path 4, and the movement of the rod 20 of the second hydraulic cylinder 2 is reversed to connect the pallet to the power transmission path connecting the second hydraulic cylinder 2 and the pallet 3. A power reversing mechanism 5 is interposed to transmit the power to the motor.

In the above structure, as shown in FIG. 2 or 3, the communication path 4 is provided with a discharge means 7 for discharging excess oil from a line connecting each rod side chamber 12, 22, and a discharge means 7 for discharging insufficient oil into this line. It is preferable to connect a correction circuit 9 having a replenishing means 8 for replenishing.

[0008]

[Operation] By introducing pressure oil into the head side chamber 11 of the first hydraulic cylinder 1, the first hydraulic cylinder 1 moves forward, and the oil flowing out from the rod side chamber 11 is transferred to the second hydraulic pressure It flows into the rod side chamber 22 of the cylinder 2, and the second hydraulic cylinder 2 moves backward. In this way, the pallet 3 is moved to one side by the operation of the first hydraulic cylinder 1 and the operation of the second hydraulic cylinder 2 via the power reversing mechanism 5. In this case, since the amount of oil flowing out from the rod side chamber 11 of the first hydraulic cylinder 1 and the amount of oil flowing into the rod side chamber 22 of the second hydraulic cylinder 2 are equal, regardless of the unbalance of the load acting on the pallet 3, The operating strokes of the hydraulic cylinders 1 and 2 can be made equal, and the pallet 3 can be moved in parallel without being tilted.

On the other hand, the head side chamber 1 of the first hydraulic cylinder 1
1 to the tank, the first hydraulic cylinder 1 moves backward, and oil flows from the rod side chamber 22 of the second hydraulic cylinder 2 through the communication path 4 into the rod side chamber 11 whose volume increases. The two hydraulic cylinders 2 move forward. In this way, the pallet 3 can be moved to the other side, but in this case as well, the amount of oil flowing into the rod side chamber 12 of the second hydraulic cylinder 1 and the amount of oil flowing out from the rod side chamber 22 of the second hydraulic cylinder 2 are equal. , the operating strokes of the hydraulic cylinders 1 and 2 can be made equal, and the pallet 3 can be moved in parallel.

By connecting a correction circuit 9 having a discharge means 7 and a supply means 8 to the communication path 4, each rod side chamber 1
When the amount of oil in the line connecting the rod side chambers 12 and 22 increases, the excess oil can be discharged through the discharge means 7, and when the amount of oil in the line connecting the rod side chambers 12 and 22 decreases, the excess oil can be removed. Since oil can be replenished by the replenishing means 8, even if there is a fluctuation in the amount of oil exchanged between each rod side chamber 12, 22 due to internal leakage of the cylinder, the fluctuation can be absorbed.
Each hydraulic cylinder 1, 2 can reach its scroll end in a good manner, and it is possible to prevent the height of the pallet 3 from shifting due to leakage in the raised and lowered positions.

[0011]

[Embodiment] The hydraulic multilevel parking system shown in FIG. Movable pulleys 14 and 24 are attached to the tips of the rods 10 and 20 via brackets 13 and 23, and a first lifting transmission such as a chain is provided between one side of the pallet 3 and the fixed end F1. body 61, the other side of the pallet 3 and the fixed end F
The pallet 3 is raised and lowered by lifting and lowering a second lifting power transmission body 62, which is also a chain or the like, which is stretched between the pallet 3 and the pallet 3.

With the above configuration, the connection to the head side chamber 11 of the first hydraulic cylinder 1 is switched via the solenoid type switching valve V to the discharge line H extending from the hydraulic pump P and the tank line D1 leading to the tank T1. Connect pressure line R. The pressure line R is equipped with a parallel circuit of a throttle F and a check valve C, and a pilot check valve J. The switching valve V is switched to the symbol position on the left in the figure by energizing the first solenoid S1, and the hydraulic pump P is switched from the tank T2. Pressure oil pumped up through the valve is introduced into the head side chamber 11 through the pilot check valve J and check valve C, and the switching valve V is switched to the symbol position on the right in the figure by energizing the second solenoid S2, and the pilot check J is opened. The head side chamber 11 is opened to the tank T1 through the throttle F. Note that a high pressure relief valve L communicating with the tank T3 is connected to the discharge line H.

Furthermore, the head side chamber 21 of the second hydraulic cylinder 2
is connected to the tank line D2 leading to the tank T4, while each rod side chamber 1 of the first and second hydraulic cylinders 1, 2
2 and 22 are connected to each other via a communication path 4.

Furthermore, the power transmission path connecting the movable pulley 24 attached to the second hydraulic cylinder 2 and the pallet 3 is constructed using a fixed pulley 51 supported at the fixed end F3 via a bracket 50, and the second A power reversing mechanism 5 is provided to reverse the operation of the rod 20 of the hydraulic cylinder 2 and transmit it to the pallet 3.

In this way, the first solenoid S1 of the switching valve V
, by introducing pressure oil from the hydraulic pump P into the head side chamber 11 of the first hydraulic cylinder 1, the rod 1
0 advances and one side of the pallet 3 is lifted up. At the same time, as the rod 10 of the first hydraulic cylinder 1 advances, oil flowing out from the rod side chamber 11 flows into the rod side chamber 22 of the second hydraulic cylinder 2 via the communication path 4, and the rod of the second hydraulic cylinder 2 20 is retreated, and the other side of the pallet 3 is also lifted up via the power reversing mechanism 5. in this case,
Since the amount of oil flowing out from the rod side chamber 11 of the first hydraulic cylinder 1 and the amount of oil flowing into the rod side chamber 22 of the second hydraulic cylinder 2 are equal, each rod The operating strokes of the pallets 10 and 20 are equal, and the pallet 3 rises in parallel without tilting in a state in which left and right sides are synchronized.

In the raised position, each solenoid S of the switching valve V
1. Turn off S2 and set the switching valve V to the neutral position shown in the figure.
By preventing backflow by the pilot check valve J, pressure is maintained on the head side chamber 11 side of the first hydraulic cylinder 1, and its raised position is maintained.

On the other hand, by energizing the second solenoid S2 of the switching valve V, the head side chamber 11 of the first hydraulic cylinder 1 is connected to the tank T.
1, the rod 10 is attached to the pallet 3.
The weight of the vehicle W causes it to move backward, and one side of the pallet 3 is suspended. At the same time, as the rod 10 of the first hydraulic cylinder 1 retreats, the rod side chamber 11 whose volume increases
to the rod side chamber 2 of the second hydraulic cylinder 2 via the communication path 4.
2, the weight of the pallet 3 and the vehicle W allows the rod 20 of the second hydraulic cylinder 2 to advance, and the other side of the pallet 3 is also suspended. In this case as well, since the amount of oil flowing into the rod side chamber 12 of the second hydraulic cylinder 1 and the amount of oil flowing out from the rod side chamber 22 of the second hydraulic cylinder 2 are equal, the operating strokes of each rod 10, 20 are equal. Therefore, the pallet 3 descends in parallel without being tilted in a state in which the left and right sides are synchronized.

[0018] The movement of each rod 10, 20 is based on the movable pulley 1.
4, 24 to the pallet 3, so that the pallet 3 is raised and lowered over a height corresponding to twice the stroke of each rod 10, 20.

By the way, with the above configuration, each rod side chamber 1
If there is a fluctuation in the amount of oil due to leakage in the line connecting 2 and 22, a situation may occur in which the left and right heights of the pallet 3 differ slightly between the raised and lowered positions. That is, for example, if the amount of oil in the line connecting each rod side chamber 12, 22 increases due to internal leakage of the cylinder, etc., by lifting the pallet 3 from the bottom to the top, the second hydraulic cylinder 2, which is the oil inflow side, is moved. The rod 20 stops at the lower stroke end, but
The rod 10 of the first hydraulic cylinder 1 on the oil outflow side does not reach the upper stroke end. In addition, if the amount of oil in the line connecting the rod side chambers 12 and 22 decreases, by lowering the pallet 3 from the top to the bottom, the rod 20 of the second hydraulic cylinder 2, which is the oil outlet side, will be moved to the upper stroke end. However, the rod 10 of the first hydraulic cylinder 1, which is the oil inflow side, does not reach the lower stroke end.

In this case, it is possible to deal with the problem by preventing internal leakage of each hydraulic cylinder 1, 2, but as shown in FIG.
, 22, and a check valve 81 that replenishes insufficient oil from tank T6 to this line and only allows flow out from the tank T6 side. Preferably, a correction circuit 9 comprising replenishment means 8 is connected.

According to this, the amount of oil in the line connecting each rod side chamber 12, 22 increases, and when the pallet 3 is lifted,
Even if the rod 20 of the second hydraulic cylinder 2, which is the oil inflow side, has already reached the lower stroke end, the pressure in the communication passage 4 increases as the rod 10 of the first hydraulic cylinder 1 rises, and the relief valve 71 closes. Since the valve is opened, the oil flowing out from the rod side chamber 12 of the first hydraulic cylinder 1 flows through the relief valve 71.
through the tank T5, and the first hydraulic cylinder 1
The rod 10 can reach the upper stroke end, so that the left and right heights of the pallet 3 can be made equal.

Furthermore, the amount of oil in the line connecting the rod side chambers 12 and 22 has decreased, and when the pallet 3 is lowered, the rod 20 of the second hydraulic cylinder 2, which is the oil outlet side, has already reached the upper stroke end. However, as the rod 10 of the first hydraulic cylinder 1 descends, the pressure in the communication path 4 becomes negative pressure and oil is replenished from the tank T6 via the check valve 81. The side chamber 12 is filled with oil commensurate with the increase in volume, and the first hydraulic cylinder 1
The rod 10 can reach the lower stroke end, so that the left and right heights of the pallet 3 can be made equal.

In FIG. 2, the replenishment means 8 is directly connected to the tank T6 via a check valve 81,
Oil is replenished when the pressure in the communication path 4 becomes lower than the tank pressure, but as shown in FIG. In addition, the pressure is set lower than the pressure in the communication path 4 when oil is normally exchanged between the head side chambers 12 and 22, and a relief valve 83 having a discharge path to the tank T7 and the communication path 4 side are connected to each other. The replenishment means 8 is configured using a check valve 81 that only allows replenishment of oil, and when the pressure in the communication passage 4 becomes lower than the relief setting pressure set by the relief valve 83, the replenishment means 8 is Alternatively, the communication path 4 may be refilled with oil.

[0024]

As described above, according to the present invention, the two cylinders, the first and second hydraulic cylinders 1 and 2, can be controlled with a simple configuration consisting only of the hydraulic circuit without the need for a separate mechanical tuning mechanism. The operations can be synchronized well regardless of the unbalance of the load acting on the pallet 3, and the pallet 3 can be moved up and down well while preventing its tilting.

In addition, when the correction circuit 9 comprising the discharge means 7 and the replenishment means 8 is provided, even when oil amount fluctuation occurs in the line connecting the rod side chambers 12 and 22 of each hydraulic cylinder 1 and 2 due to leakage, , it is possible to satisfactorily correct the height deviation between the raised and lowered positions of the pallet 3.

[Brief explanation of drawings]

FIG. 1 is a hydraulic circuit diagram showing a first embodiment of a hydraulic multilevel parking system according to the present invention.

FIG. 2 is a hydraulic circuit diagram showing the second embodiment.

FIG. 3 is a hydraulic circuit diagram showing the third embodiment.

[Explanation of symbols]

1 First hydraulic cylinder 2 Second hydraulic cylinder 3 Palette 4. Connection route 5　Power reversal mechanism 7. Discharge means 8. Supply means 9 Correction circuit 11, 21 Head side chamber 12, 22 Rod side chamber 20 Rod

Claims (2)

[Claims] 1. A hydraulic multi-level parking system in which a pallet 3 for mounting on a vehicle is raised and lowered by a hydraulic lifting device including first and second hydraulic cylinders 1 and 2, wherein a head side chamber of the first hydraulic cylinder 1 11 to a pressure line whose connection is switched between a discharge line extending from the hydraulic pump and a tank line leading to the tank, and connecting the head side chamber 21 of the second hydraulic cylinder 2 to the tank line leading to the tank, The first and second hydraulic cylinders 1
, 2 are connected to each other via a communication path 4, and the second hydraulic cylinder 2 and the pallet 3 are
A hydraulic multi-level parking system characterized in that a power reversing mechanism 5 for reversing the operation of the rod 20 of the second hydraulic cylinder 2 and transmitting the same to the pallet 3 is interposed in a power transmission path connecting the two. 2. A correction circuit 9 is connected to the communication path 4, and includes a discharge means 7 for releasing excess oil from a line connecting the rod side chambers 12 and 22, and a replenishment means 8 for supplying insufficient oil to this line. The hydraulic multilevel parking system according to claim 1.