Hydraulic logic control system for sidesway distance adjusting fork

Abstract

The utility model discloses a hydraulic logic control system for a sidesway distance adjusting fork. Comprising an oil pump, a safety valve, a first reversing valve plate, a logic control valve block, a first hydraulic control one-way valve, a first three-way pipe, a right pallet fork distance adjusting oil cylinder, a left pallet fork distance adjusting oil cylinder, a first overload valve, a second hydraulic control one-way valve, a second three-way pipe, a third three-way pipe, a third hydraulic control one-way valve, a throttling valve, a second reversing valve plate and a second overload valve. The logic control valve block comprises a second hydraulic control one-way valve, a third hydraulic control one-way valve, a throttling valve and a second overload valve, and the second hydraulic control one-way valve, the third hydraulic control one-way valve, the throttling valve and the second overload valve are communicated through pipelines. And the first reversing valve plate is communicated with the second reversing valve plate. According to the hydraulic logic control system for the laterally-moving distance adjusting fork, the purpose of hydraulic oil way regulation and control is achieved through the arrangement of the structure.

Description

TECHNICAL FIELD

[0001] The utility model relates to hydraulic system technical field, concretely is a kind of hydraulic logic control system for side shift distance adjusting fork. BACKGROUND

[0002] Forklift is mainly used to fork material, realizes the carrying work of material, forklift is usually configured different accessory to expand the use range of forklift, to meet the requirement of different forklift operating environments, side shift distance adjusting fork is a kind of accessory commonly used in forklift, it is through pump and multiway valve oil supply to adjust oil cylinder, push fork to realize the side shift and distance adjusting function of fork.The deficiencies of existing side shift distance adjusting fork accessory hydraulic system mainly have the following points:

[0003] 1.fork side shift needs separate oil cylinder control to realize, distance adjusting is controlled by setting two oil cylinders, and the structure is complex and heavy, not economical;

[0004] 2.two forks are controlled by two oil cylinders to distance adjusting movement, single fork left and right distance adjusting (another fork is not moved), time-consuming and laborious, and work efficiency is low;

[0005] 3.there is also through the increase of solenoid valve to realize the distance adjusting action (expansion and contraction) between two forks, not only poor speed control characteristic, and because of pressure impact in running process, easy to cause oil cylinder piston rod deformation damage.

[0006] 4.during the left and right side shift of fork, when the stroke of one oil cylinder is in place, the stroke of another oil cylinder is not in place, because of the inevitable internal leakage of control valve core, causes another oil cylinder action problem. INVENTION CONTENTS

[0007] The utility model aims at providing a kind of hydraulic logic control system for side shift distance adjusting fork, to solve the problems raised in the above background technology.

[0008] To realize the above-mentioned purpose, the utility model provides the following technical scheme: a kind of hydraulic logic control system for side shift distance adjusting fork, including oil pump, safety valve, first reversing valve piece, logic control valve block, first hydraulic control check valve, first tee pipe, right fork distance adjusting oil cylinder, left fork distance adjusting oil cylinder, first overload valve, second hydraulic control check valve, second tee pipe, third tee pipe, third hydraulic control check valve, throttle valve, second reversing valve piece and second overload valve;

[0009] The logic control valve block includes second hydraulic control check valve, third hydraulic control check valve, throttle valve and second overload valve, and second hydraulic control check valve, third hydraulic control check valve, throttle valve and second overload valve are communicated by pipeline setting;

[0010] The first reversing valve piece is communicated with the second reversing valve piece, the oil pump is communicated with the second overload valve, and the oil pump is further communicated with the oil tank through a safety valve, the first reversing valve piece, the second reversing valve piece and the oil tank are communicated, the first reversing valve piece is communicated with a logic control valve block, the logic control valve block is communicated with a first three-way pipe, and the first three-way pipe is communicated with a right fork distance adjusting oil cylinder, and meanwhile, the first three-way pipe is also communicated with a left fork distance adjusting oil cylinder.

[0011] Specifically, the second three-way pipe is communicated with the second reversing valve piece, the second three-way pipe is further communicated with the logic control valve block and the left fork distance adjusting oil cylinder, the second reversing valve piece is communicated with a third three-way pipe, and the third three-way pipe is communicated with the logic control valve block and the right fork distance adjusting oil cylinder.

[0012] Specifically, the first overload valve is communicated with the logic control valve block, and the second overload valve is communicated with the logic control valve block.

[0013] Specifically, the logic control valve block is controlled to be communicated through a second hydraulic control check valve and a third hydraulic control check valve.

[0014] Specifically, the first overload valve and the second overload valve are used for limiting the maximum pressure of the rod cavities of the left fork distance adjusting oil cylinder and the right fork distance adjusting oil cylinder and preventing impact caused by excessively high pressure.

[0015] Specifically, the throttle valve is used for bypass unloading and adjusting the movement speed of the two cavities of the oil cylinder.

[0016] Compared with the prior art, the utility model has the advantages that:

[0017] 1. The utility model utilizes two oil cylinders and three hydraulic control check valves, realizes side shift function and double fork distance adjusting function through logical conversion design of the oil circuit, and has simple system structure, comprehensive function and convenient operation.

[0018] 2. The utility model realizes side shift distance adjusting action of double oil cylinders driving double forks through the hydraulic control check valve arranged on the accessory oil circuit, avoids the problem that one oil cylinder continues to act after the stroke of the oil cylinder is in place, and improves the safety of side shift operation.

[0019] 3. The overload valve is arranged in the oil circuit of the logic valve block, prevents impact damage of the oil cylinder caused by excessively high pressure, improves the service life of the accessory, and the throttle valve is arranged in parallel in the oil circuit of the logic valve block, plays the bypass unloading role on one hand, and can adjust the movement speed of the oil cylinder on the other hand. DRAWINGS

[0020] Figure 1 It is a schematic diagram of the main body structure of the utility model.

[0021] In the figure: 1-oil pump; 2-safety valve; 3-first reversing valve piece; 4-logic control valve block; 5-first hydraulic control check valve; 6-first three-way pipe; 7-right fork distance adjusting oil cylinder; 8-left fork distance adjusting oil cylinder; 9-first overload valve; 10-second hydraulic control check valve; 11-second three-way pipe; 12-third three-way pipe; 13-third hydraulic control check valve; 14-throttle valve; 15-second reversing valve piece; 16-second overload valve; 17-oil tank. DETAILED DESCRIPTION

[0022] The technical solutions in the embodiments of the utility model will be apparently and completely described in combination with the drawings in the embodiments of the utility model. Obviously, the described embodiments are only part of the embodiments of the utility model, rather than all the embodiments. Based on the embodiments in the utility model, all other embodiments obtained by the ordinary skilled in the art without making creative efforts fall within the protection scope of the utility model.

[0023] Please refer to Figure 1 The utility model provides a kind of technical solutions: a kind of hydraulic logic control system for side shift distance adjusting fork, with the logic control of hydraulic oil circuit with side shift distance adjusting function includes oil pump 1, safety valve 2, first reversing valve piece 3, logic control valve block 4, first hydraulic control check valve 5, right fork distance adjusting oil cylinder 7, left fork distance adjusting oil cylinder 8, first overload valve 9, second hydraulic control check valve 10, third hydraulic control check valve 13, throttle valve 14, second reversing valve piece 15, second overload valve 16, oil tank 17 etc.

[0024] The first reversing valve piece 3 and second reversing valve piece 15 are connected in parallel.

[0025] The logic control valve block 4 has five working oil ports, which are first working oil port V1 and second working oil port V2 connected with reversing valve, third working oil port C1, fourth working oil port C2 and fifth working oil port C3 connected with oil cylinder.

[0026] Characteristics: the oil suction port of the oil pump 1 communicates with the hydraulic oil tank 16, the oil outlet of the oil pump 1 is divided into two ways, one way is connected to the inlet of the system safety valve 2, the outlet of the safety valve 2 communicates with the oil tank 17; the other way is connected to the oil inlet P of the parallelly connected first reversing valve piece 3 and second reversing valve piece 15; the oil return port T of the parallelly connected first reversing valve piece 3 and second reversing valve piece 15 communicates with the oil tank 17. The first working oil port A1 of the first reversing valve piece 3 communicates with the first working oil port V1 of the logic control valve block 4; the second working oil port B1 of the first reversing valve piece 3 communicates with the second working oil port V2 of the logic control valve block 4.

[0027] The first working oil port V1 in the logic control valve block 4 communicates with the throttle valve oil port a, the working oil port D of the first hydraulic control check valve 5, the oil return port f of the second overload valve 16, the oil inlet port c of the first overload valve 9, the control oil channel of the second hydraulic control check valve 10 and the third hydraulic control check valve 13. The second working oil port V2 communicates with the throttle valve oil port b, the working oil port E of the second hydraulic control check valve 10, the working oil port F of the third hydraulic control check valve 13, the oil inlet port e of the second overload valve 16, the oil outlet port d of the first overload valve 9 and the control oil channel of the first hydraulic control check valve 5.

[0028] The third working oil port C1 of the logic control valve block 4 communicates with the first interface of the first three-way pipe 6; the second interface of the first three-way pipe 6 communicates with the rod cavity of the right fork distance adjusting oil cylinder 7; the third interface of the first three-way pipe 6 communicates with the rod cavity of the left fork distance adjusting oil cylinder 8.

[0029] The first working oil port A2 of the second reversing valve piece 15 communicates with the first interface of the second three-way pipe 11; the second interface of the second three-way pipe 11 communicates with the fourth working oil port C2 of the logic control valve block 4; the third interface of the second three-way pipe 11 communicates with the rodless cavity of the left fork distance adjusting oil cylinder 8. The second working oil port B2 of the second reversing valve piece 15 communicates with the first interface of the third three-way pipe 12; the second interface of the third three-way pipe 12 communicates with the fifth working oil port C3 of the logic control valve block 4; the third interface of the third three-way pipe 12 communicates with the rodless cavity of the right fork distance adjusting oil cylinder 7.

[0030] When the first reversing valve piece 3 and the second reversing valve piece 15 are in the neutral position, the oil inlet port P communicates with the oil return port T, and the oil return port T communicates with the hydraulic oil tank 17.

[0031] The oil inlet port c of the first overload valve 9 communicates with the first working oil port V1 of the logic control valve block 4; the oil outlet port d of the first overload valve 9 communicates with the second working oil port V2 of the logic control valve block 4.

[0032] The oil inlet e of the second overload valve 16 is communicated with the second working oil port V2 of the logic control valve block 4; the oil outlet f of the second overload valve 16 is communicated with the first working oil port V1 of the logic control valve block 4.

[0033] When the first working oil port V1 of the logic control valve block 4 is communicated with pressure oil, the working oil port D of the first hydraulic control check valve 5 is communicated with the third working oil port C1 of the logic control valve block 4 in positive direction; meanwhile, the second hydraulic control check valve 10 and the third hydraulic control check valve 13 are communicated in reverse direction through the internal control oil path of the second hydraulic control check valve 10 and the third hydraulic control check valve 13 communicated with the first working oil port V1 of the logic control valve block 4, that is, the fourth working oil port C2 and the working oil port E of the second hydraulic control check valve 10 are communicated, and the fifth working oil port C3 and the working oil port F of the third hydraulic control check valve 13 are communicated. When the second working oil port V2 of the logic control valve block 4 is communicated with pressure oil, the working oil port E of the second hydraulic control check valve 10 is communicated with the fourth working oil port C2 of the logic control valve block 4 in positive direction; the working oil port F of the third hydraulic control check valve 13 is communicated with the fifth working oil port C3 of the logic control valve block 4 in positive direction. Meanwhile, the first hydraulic control check valve 5 is communicated in reverse direction through the internal control oil path of the first hydraulic control check valve 5 communicated with the second working oil port V2 of the logic control valve block 4, that is, the third working oil port C1 of the logic control valve block 4 is communicated with the working oil port D of the first hydraulic control check valve 5. Conversely, when the third working oil port C1 of the logic control valve block 4 is communicated with pressure oil, and the control oil path of the first hydraulic control check valve 5 is not communicated with pressure oil, the first hydraulic control check valve 5 is closed in reverse direction, and the third working oil port C1 of the logic control valve block 4 is not communicated with the working oil port D of the first hydraulic control check valve 5. When the fourth working oil port C2 or the fifth working oil port C3 of the logic control valve block 4 is communicated with pressure oil, and the control oil path of the second hydraulic control check valve 10 and the third hydraulic control check valve 13 is not communicated with pressure oil, the second hydraulic control check valve 10 and the third hydraulic control check valve 13 are closed in reverse direction, and the fourth working oil port C2 of the logic control valve block 4 is not communicated with the working oil port E of the second hydraulic control check valve 10, and the fifth working oil port C3 of the logic control valve block 4 is not communicated with the working oil port F of the third hydraulic control check valve 13.

[0034] The functions of the first overload valve 9 and the second overload valve 16 limit the maximum pressure of the rod cavity of the left and right fork distance adjusting oil cylinder and prevent the impact caused by the over-high pressure.

[0035] The function of the throttle valve 14 is to bypass unloading and adjust the movement speed of the two cavities of the oil cylinder.

[0036] Working principle: when the fork does not need to move, the first reversing valve plate 3 and the second reversing valve plate 15 are both in the middle position, the oil inlet P is communicated with the oil return port T, and the hydraulic oil output by the oil pump 1 flows back to the hydraulic oil tank 17 through the middle oil passage.

[0037] When the forklift fork does side movement, the second reversing valve piece 15 is in the reversing position, when the pressure oil output by the oil pump 1 is connected with the first working oil port A2 of the second reversing valve piece 15 through the oil inlet P, the pressure oil output by the oil pump 1 passes through the first working oil port A2 of the second reversing valve piece 15, the second three-way pipe 11 to the rodless cavity of the left fork distance adjusting oil cylinder 8, pushes the left fork distance adjusting oil cylinder 8 piston rod to drive the fork to move left, the pressure oil output by the rod cavity of the left fork distance adjusting oil cylinder 8 passes through the first three-way pipe 6 to the rod cavity of the right fork distance adjusting oil cylinder 7, pushes the right fork distance adjusting oil cylinder 7 piston rod to drive the fork to move left, the pressure oil output by the rodless cavity of the right fork distance adjusting oil cylinder 7 passes through the third three-way pipe 12, the second working oil port B2 of the second reversing valve piece 15 back to the oil tank, realizing the left side movement of the fork. Similarly, when the pressure oil output by the oil pump 1 is connected with the second working oil port B2 of the second reversing valve piece 15, the pressure oil output by the oil pump 1 passes through the second working oil port B2 of the second reversing valve piece 15, the third three-way pipe 12 to the rodless cavity of the right fork distance adjusting oil cylinder 7, pushes the right fork distance adjusting oil cylinder 7 piston rod to drive the fork to move right, the pressure oil output by the rod cavity of the right fork distance adjusting oil cylinder 7 passes through the first three-way pipe 6 to the rod cavity of the left fork distance adjusting oil cylinder 8, pushes the left fork distance adjusting oil cylinder 8 piston rod to drive the fork to move right, the pressure oil output by the rodless cavity of the left fork distance adjusting oil cylinder 8 passes through the second three-way pipe 11, the first working oil port A2 of the second reversing valve piece 15 back to the oil tank, realizing the right side movement of the fork. In the process of left and right side movement of the fork, when one oil cylinder stroke is in place and the other oil cylinder stroke is not in place, such as in the process of left side movement, the right fork distance adjusting oil cylinder 7 stroke is in place and the left fork distance adjusting oil cylinder 8 stroke is not in place, because the rod cavities of the left and right fork distance adjusting oil cylinders are connected with the third working oil port C1 of the logic control valve block 4 and the first hydraulic control check valve 5, and the first hydraulic control check valve 5 has no pressure oil and is in reverse blocking state, so it can prevent another oil cylinder from moving due to valve block leakage.

[0038] When the forklift forks need to do double fork distance adjustment action, the first reversing valve piece 3 is in the reversing position. When the pressure oil output by the oil pump 1 is connected with the first working oil port A1 of the first reversing valve piece 3, the pressure oil output by the oil pump 1 reaches the first working oil port V1 of the logic control valve block 4 through the first working oil port A1 of the first reversing valve piece 3, and is divided into six ways through the first working oil port V1, one way reaches the throttle valve 14 working port a; one way reaches the working oil port D of the first double-acting hydraulic lock 5; one way reaches the inlet c of the overload valve 9; one way reaches the oil outlet f of the second overload valve 16, and the second overload valve 16 is reverse cut-off. The other two ways respectively enter the control oil ways of the second hydraulic control check valve 10 and the third hydraulic control check valve 13, so that the second hydraulic control check valve 10 and the third hydraulic control check valve 13 are reverse on. The pressure oil reaches the working oil port D of the first double-acting hydraulic lock 5, and reaches the rod cavity of the right fork distance adjustment oil cylinder 7 and the left fork distance adjustment oil cylinder 8 through the third working oil port C1 of the logic control valve block 4 and the first three-way pipe 6 respectively, drives the right fork distance adjustment oil cylinder 7 piston rod to drive the fork to move left, and drives the left fork distance adjustment oil cylinder 8 piston rod to drive the fork to move right. Since the control oil ways of the second hydraulic control check valve 10 and the third hydraulic control check valve 13 are connected with pressure oil, they are reverse on, so the pressure oil output by the rodless cavity of the right fork distance adjustment oil cylinder 7 flows back to the oil tank through the third three-way pipe 12, the fifth working oil port C3 of the logic control valve block 4, the working oil port F of the third hydraulic control check valve 13, the second working oil port V2 of the logic control valve block 4, and then the second working oil port B1 of the first reversing valve piece 3; the pressure oil output by the rodless cavity of the left fork distance adjustment oil cylinder 8 flows back to the oil tank through the second three-way pipe 11, the fourth working oil port C2 of the logic control valve block 4, the working oil port E of the second hydraulic control check valve 10, the second working oil port V2 of the logic control valve block 4, and then the second working oil port B1 of the first reversing valve piece 3. The double fork simultaneous contraction action is realized. The function of the first overload valve 9 is to prevent the impact caused by the high pressure in the rod cavity of the left and right fork distance adjustment oil cylinders in the simultaneous contraction process. The function of the throttle valve 14 is to bypass unloading (oil discharge) to adjust the contraction speed of the two oil cylinders.

[0039] When the forklift forks need to do double fork distance adjustment action, the first reversing valve piece 3 is in the reversing position. When the pressure oil output by the oil pump 1 is connected with the second working oil port B1 of the first reversing valve piece 3, the pressure oil output by the oil pump 1 reaches the second working oil port V2 of the logic control valve block 4 through the second working oil port B1 of the first reversing valve piece 3, and is divided into six ways through the second working oil port V2, one way reaches the working port b of the throttle valve 14; one way reaches the control oil way of the first hydraulic control check valve 5, so that the first hydraulic control check valve 5 is reversely conducted; one way reaches the working oil port F of the third hydraulic control check valve 13; one way reaches the working oil port E of the second hydraulic control check valve 10; one way reaches the outlet d of the first overload valve 9, and the first overload valve 9 is reversely cut off. The pressure oil reaches the working oil port F of the third hydraulic control check valve 13, reaches the rodless cavity of the right fork distance adjustment oil cylinder 7 through the fifth working oil port C3 and the third three-way pipe 12 of the logic control valve block 4, and drives the right fork distance adjustment oil cylinder 7 piston rod to move the fork to the right; the pressure oil reaches the working oil port E of the second hydraulic control check valve 10, reaches the rodless cavity of the left fork distance adjustment oil cylinder 8 through the fourth working oil port C2 and the second three-way pipe 11 of the logic control valve block 4, and drives the left fork distance adjustment oil cylinder 8 piston rod to move the fork to the left. The pressure oil output by the rod cavities of the right fork distance adjustment oil cylinder 7 and the left fork distance adjustment oil cylinder 8 is converged through the first three-way pipe 6, and then flows back to the oil tank through the third working oil port C1 of the logic control valve block 4, the working oil port D of the first hydraulic control check valve 5, the first working oil port V1 of the logic control valve block 4, and then the first working oil port A1 of the first reversing valve piece 3. The double fork opening action is realized. The second overload valve 16 prevents the impact caused by the pressure of the rodless cavities of the left and right fork distance adjustment oil cylinders being too high during the simultaneous opening process. The throttle valve 14 adjusts the opening movement speed of the two oil cylinders and completes the work.

[0040] Although the embodiments of the present application have been shown and described, it is to be understood that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the present application, and the scope of the present application is defined by the appended claims and their equivalents.

Claims

1. A hydraulic logic control system for a side shift indexing fork, characterized by: The oil pump (1), the safety valve (2), the first reversing valve (3), the logic control valve block (4), the first hydraulic control check valve (5), the first three-way pipe (6), the right fork distance adjusting oil cylinder (7), the left fork distance adjusting oil cylinder (8), the first overload valve (9), the second hydraulic control check valve (10), the second three-way pipe (11), the third three-way pipe (12), the third hydraulic control check valve (13), the throttle valve (14), the second reversing valve (15) and the second overload valve (16) are included. The logic control valve block (4) includes the second hydraulic control check valve (10), the third hydraulic control check valve (13), the throttle valve (14) and the second overload valve (16), and the second hydraulic control check valve (10), the third hydraulic control check valve (13), the throttle valve (14) and the second overload valve (16) are connected by pipelines. The first reversing valve (3) is connected with the second reversing valve (15), the oil pump (1) is connected with the second overload valve (16), and the oil pump (1) is also connected with the oil tank (17) through the safety valve (2), the first reversing valve (3) and the second reversing valve (15) are connected with the oil tank (17), the first reversing valve (3) is connected with the logic control valve block (4), the logic control valve block (4) is connected with the first three-way pipe (6), the first three-way pipe (6) is connected with the right fork distance adjusting oil cylinder (7), and the first three-way pipe (6) is also connected with the left fork distance adjusting oil cylinder (8).

2. A hydraulic logic control system for a side shift indexing fork as defined in claim 1, wherein: The second three-way pipe (11) is connected with the second reversing valve (15), the second three-way pipe (11) is also connected with the logic control valve block (4) and the left fork distance adjusting oil cylinder (8), the second reversing valve (15) is connected with the third three-way pipe (12), and the third three-way pipe (12) is connected with the logic control valve block (4) and the right fork distance adjusting oil cylinder (7).

3. A hydraulic logic control system for a side shift indexing fork as defined in claim 2 wherein: The first overload valve (9) is connected with the logic control valve block (4), and the second overload valve (16) is connected with the logic control valve block (4).

4. A hydraulic logic control system for a side shift indexing fork as defined in claim 3 wherein: The logic control valve block (4) is connected through the second hydraulic control check valve (10) and the third hydraulic control check valve (13).

5. A hydraulic logic control system for a side shift ratio fork as defined in claim 4, wherein: The first overload valve (9) and the second overload valve (16) are used for limiting the maximum pressure of the rod cavity of the left and right fork distance adjusting oil cylinders and preventing the impact caused by the excessively high pressure.

6. A hydraulic logic control system for a side shift indexing fork as defined in claim 5 wherein: The throttle valve (14) is used for bypass unloading and adjusting the movement speed of the two cavities of the oil cylinder.

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