CN111704080B

CN111704080B - Oil circuit system of forklift gantry

Info

Publication number: CN111704080B
Application number: CN202010437555.8A
Authority: CN
Inventors: 金汝灯; 辛光辉; 方晓晖; 毛云杰; 胡斌; 毛烨鑫
Original assignee: Hangzhou Forklift Gantry Co ltd
Current assignee: Hangzhou Forklift Gantry Co ltd
Priority date: 2020-05-21
Filing date: 2020-05-21
Publication date: 2021-08-31
Anticipated expiration: 2040-05-21
Also published as: CN111704080A

Abstract

The invention discloses an oil circuit system of a forklift gantry, which relates to the technical field of forklifts and adopts the technical scheme that the oil circuit system comprises a frame body, a front hydraulic cylinder arranged on the frame body, a rear hydraulic cylinder arranged on the frame body, a main oil circuit for providing power for the front hydraulic cylinder and the rear hydraulic cylinder, a triple oil circuit and a quadruple oil circuit for providing power for accessories and positioned at two sides of the frame body, and a pulley mechanism arranged on the frame body for providing support for the oil circuit. The invention has the effect of reducing the obstruction of the oil path to the visual field of a driver.

Description

Oil circuit system of forklift gantry

Technical Field

The invention relates to the technical field of forklifts, in particular to an oil circuit system of a forklift gantry.

Background

The basic functions of loading, unloading, carrying and stacking goods of the truck are composed of a portal frame and accessories, and in order to improve the lifting height of the portal frame or reduce the lowest structural height of a forklift, a three-level portal frame is mostly used at present. The three-stage portal frame is a three-section telescopic device consisting of an outer portal frame, a middle portal frame and an inner portal frame. When the portal frame rises, the fork frame moves along the inner portal frame, the inner portal frame moves along the middle portal frame, and the middle portal frame moves along the outer portal frame, so that the rising height of the portal frame is expanded. In order to perfect and compensate the performance of the forklift and meet the requirement of complex and diversified loading and unloading of modern logistics storage, the fork frame of the forklift can be provided with different accessories so as to meet different working environments. The accessory provides power through a hydraulic system. The oil tank and the accessory for supplying oil to the forklift hydraulic system are located on the front side and the rear side of the portal frame, and the portal frame needs to be lifted in the working process, so that the distance between the accessory and the oil tank is changed. If the oil pipe directly passes through the middle of the door frame, the oil supply pipeline is easily interfered by the operation of the door frame, so that the phenomena of extrusion, breakage, oil leakage, blockage and the like are caused, and the service life of the oil pipe is influenced.

The oil circuit of current fork truck portal arranges in portal rear portion both sides basically, and horizontal or put the overall arrangement to one side, and the advantage is that the commonality is better, and fork truck portal sprocket can all borrow this set of arrangement scheme. However, the oil circuit can affect the visual field of a forklift driver, affect the carrying effect of the driver on goods and even cause accidents.

Disclosure of Invention

Aiming at the defects in the prior art, the invention aims to provide the forklift mast oil circuit system, which reduces the obstruction of the oil circuit to the view of a driver by changing the arrangement of the oil circuit.

In order to achieve the purpose, the invention provides the following technical scheme: an oil circuit system of a forklift gantry comprises a frame body, a front hydraulic cylinder arranged on the frame body, a rear hydraulic cylinder arranged on the frame body, a main oil circuit for providing power for the front hydraulic cylinder and the rear hydraulic cylinder, a triple oil circuit and a quadruple oil circuit for providing power for accessories and positioned on two sides of the frame body, and a pulley mechanism arranged on the frame body for providing support for the oil circuit; the frame body comprises an outer door frame, a middle door frame, an inner door frame, a fork frame body connected to the inner door frame in a sliding mode, a first driving assembly, a second driving assembly and a plurality of pipe clamps fixed on the frame body and the rear hydraulic cylinder; an inner gantry beam is fixed on one side of the inner gantry, which is far away from the fork frame body, and an outer gantry beam is fixed on one side of the outer gantry, which is far away from the fork frame body; a first fixing block is fixed at the top end of a piston rod of the front hydraulic cylinder, and the first driving assembly comprises first chain wheels which are rotatably connected to two sides of the first fixing block and a first chain matched with the first chain wheels; the number of the rear hydraulic cylinders is two, and the two rear hydraulic cylinders are respectively arranged on two sides of one side of the frame body close to the vehicle body; a piston rod of the rear hydraulic cylinder is fixedly provided with a second fixed block, the second driving assembly comprises a second chain wheel which is rotatably connected to one side of the two second fixed blocks, which is close to each other, and a second chain which is matched with the second chain wheel, the pulley mechanism comprises a guide wheel which is arranged on one side of one of the second chain wheels, a first pulley assembly and a second pulley assembly which are arranged above the second chain wheel, and a third pulley assembly which is arranged at the top end of the front hydraulic cylinder, and the number of the guide wheels is one and is rotatably connected with the second fixed blocks; the triple oil circuit and the quadruple oil circuit respectively comprise an oil circuit pipe, a first pipe joint assembly communicated with one end of the oil circuit pipe close to the vehicle body and a second pipe joint assembly communicated with one end of the oil circuit pipe far away from the vehicle body; the first pipe joint assembly is fixed on a cross beam of the outer gantry through a pipe clamp, the oil pipeline pipe is installed on the outer gantry through the pipe clamp, bypasses the first pulley assembly, and is wound to one side, close to the vehicle body, of the front hydraulic cylinder, and is fixed on the fork frame body through the pipe clamp on one side, far away from the vehicle body, of the front hydraulic cylinder after bypassing the third pulley assembly; the main oil circuit comprises a four-way valve fixed on a cross beam of the outer gantry, a speed-limiting valve communicated with the bottom end of the four-way valve, a first oil inlet pipe and a second oil inlet pipe communicated with two sides of the four-way valve, and a front hydraulic cylinder oil inlet pipe communicated with the top end of the four-way valve; the front hydraulic cylinder oil inlet pipe is connected to the cylinder body of the front hydraulic cylinder through a guide wheel.

By adopting the technical scheme, the oil pipes (the oil path pipe and the front hydraulic cylinder oil inlet pipe) can be wound on the pulley assemblies, and the oil pipes can change along with the chains in the ascending and descending processes of the middle portal frame and the inner portal frame through the pulley assemblies, so that the extrusion and the dragging of the oil pipes caused by the change of the portal frame body are avoided; because the second sprocket sets up in the portal one side that is close to the automobile body, and the triplex oil circuit and the quadruple oil circuit from being located the first loose pulley assembly and the second loose pulley assembly of second sprocket top and bypassing, so when installation triplex oil circuit and quadruple oil circuit, can reduce triplex oil circuit and quadruple oil circuit and block the field of vision between preceding pneumatic cylinder and the interior portal, increase the scope in field of vision to reduce unexpected production.

The invention is further configured to: an oil outlet is fixed at the top end of the rear hydraulic cylinder body; an oil return pipeline is arranged on the oil outlet; the oil return pipeline comprises a first oil return pipe and a second oil return pipe which are respectively connected with the oil outlets of the two rear hydraulic cylinders, and a three-way pipe connected with the first oil return pipe and the second oil return pipe; the junction of the first oil return pipe and the second oil return pipe is positioned on one side of the frame body; the first oil return pipe is in an L shape, the vertical part is downward along the rear hydraulic cylinder, and the horizontal part passes through the outer gantry beam; the second returns oil pipe and directly follows the back pneumatic cylinder down.

Through adopting above-mentioned technical scheme, return oil pipe way and retrieve the unnecessary oil in the back pneumatic cylinder body, when first return oil pipe and second return oil pipe walked along back pneumatic cylinder body and outer portal crossbeam, not only made things convenient for the pipe clamp to fix it, but also can reduce the pipeline and stop the field of vision.

The invention is further configured to: the number of the triple oil circuit and the quadruple oil circuit is two.

By adopting the technical scheme, one of the two oil path pipes is responsible for oil inlet, the other one is responsible for oil outlet, and the two oil path pipes are in work division cooperation, so that the control effect on the accessory is improved.

The invention is further configured to: the first pulley assembly and the second pulley assembly have the same structure and respectively comprise a connecting plate in sliding connection with the second fixed block and a plurality of pulleys in rotating connection with the connecting plate; the rotating shaft of the pulley is vertical to the connecting plate, and the pulleys are arranged along the circumferential direction of the second chain wheel.

Through adopting above-mentioned technical scheme, a plurality of loose pulley assembly who arranges along the circumferencial direction of second sprocket can slow down the degree of buckling of oil circuit pipe, can prevent the damage that excessive buckling of oil circuit pipe caused the oil circuit pipe, increase relevant life.

The invention is further configured to: the first pulley component and the second pulley component further comprise supporting blocks fixed on the side edges of the second fixed blocks, fixing rods vertically fixed on the supporting blocks, sliding blocks fixed on one sides, close to the second fixed blocks, of the connecting plates and connected with the fixing rods in a sliding mode, and elastic pieces driving the sliding blocks to move in the direction away from the supporting blocks.

By adopting the technical scheme, the elastic piece can provide a buffer stroke for the movement of the connecting plate, can provide buffer for the movement of the oil path pipe when the oil path pipe moves, and reduces the dragging of the oil path pipe; when the oil path pipe is static, the tensioning device can provide tensioning for the oil path pipe, and the placing stability of the oil path pipe is improved.

The invention is further configured to: the side of second fixed block still is fixed with the stopper that can with the slider butt, and the stopper is located the below of supporting shoe.

Through adopting above-mentioned technical scheme, after the bottom of connecting plate and stopper butt, the connecting plate can't continue to slide, prevents that pulley and sprocket chain contact and the influence drive assembly work that causes.

In conclusion, the beneficial technical effects of the invention are as follows:

1. the oil pipes (an oil path pipe and a front hydraulic cylinder oil inlet pipe) can be wound on the pulley assemblies, and can change along with the chains in the ascending and descending processes of the middle door frame and the inner door frame through the pulley assemblies, so that the extrusion and the dragging of the oil pipes caused by the change of the frame body are avoided; because the second chain wheel is arranged on one side, close to the vehicle body, of the inner door frame, and the triple oil path and the quadruple oil path bypass the first pulley assembly and the second pulley assembly which are positioned at the top end of the second chain wheel, when the triple oil path and the quadruple oil path are installed, the blocking of the triple oil path and the quadruple oil path on the visual field between the front hydraulic cylinder and the inner door frame can be reduced, the visual field range is enlarged, and the occurrence of accidents is reduced;

2. the oil return pipeline recovers redundant oil in the rear hydraulic cylinder body, and when the first oil return pipe and the second oil return pipe walk, the first oil return pipe and the second oil return pipe walk along the rear hydraulic cylinder body and the outer gantry beam, so that the rear hydraulic cylinder body and the outer gantry beam are conveniently fixed by the pipe clamp, and the blockage of the pipeline to the visual field can be reduced;

3. two oil path pipes, one is responsible for the oil inlet, and the other is responsible for producing oil, and two oil pipes divide the labour to cooperate, increase the control effect to the accessory.

Drawings

FIG. 1 is a schematic view of the overall structure of the embodiment;

FIG. 2 is a plan view of a piping layout embodying an embodiment;

FIG. 3 is a schematic view of a first sheave assembly;

fig. 4 is a schematic view of a second sheave assembly.

In the figure: 1. a frame body; 11. an outer gantry; 111. an outer gantry beam; 112. a connecting plate; 113. connecting blocks; 12. a middle door frame; 13. an inner gantry; 131. an inner gantry beam; 14. a fork frame body; 15. a first drive assembly; 151. a first fixed block; 152. a first sprocket; 153. a first chain; 16. a second drive assembly; 161. a second fixed block; 162. a second sprocket; 163. a second chain; 17. a pipe clamp; 18. a first stopper; 19. a second limiting block; 2. a front hydraulic cylinder; 3. a rear hydraulic cylinder; 31. an oil outlet; 32. nylon cable ties; 4. an oil return line; 41. a first oil return pipe; 42. a second oil return pipe; 43. a three-way pipe; 5. a main oil path; 51. a four-way valve; 52. a speed limiting valve; 53. a first oil inlet pipe; 54. a second oil inlet pipe; 55. an oil inlet pipe of the front hydraulic cylinder; 6. a triple oil circuit; 61. a first pipe joint assembly; 62. a second pipe joint assembly; 63. an oil line pipe; 7. a quadruple oil circuit; 8. a pulley mechanism; 81. a guide wheel; 82. a first sheave assembly; 821. a connecting plate; 822. a pulley; 823. a support block; 824. fixing the rod; 825. a spring; 826. a slider; 827. a limiting block; 83. a second sheave assembly; 84. a third sheave assembly; 841. a support plate; 842. a support frame.

Detailed Description

The present invention will be described in further detail with reference to the accompanying drawings.

Example (b): the utility model provides a fork truck portal oil piping system, includes support body 1, the preceding pneumatic cylinder 2 of setting on support body 1, set up back pneumatic cylinder 3 on support body 1, return oil pipe way 4 with back pneumatic cylinder 3 intercommunication, for preceding pneumatic cylinder 2 and back pneumatic cylinder 3 provide the main oil circuit 5 of power, for the accessory provides power and lie in the trigeminy oil circuit 6 and the quadruple oil circuit 7 of support body 1 both sides and set up the pulley gear 8 that provides the support for the oil circuit on support body 1.

The frame body 1 comprises an outer door frame 11, a middle door frame 12, an inner door frame 13, a fork frame body 14 connected to the inner door frame 13 in a sliding mode, a first driving assembly 15 and a second driving assembly 16. The accessory is mounted on the fork frame body 14.

An inner gantry beam 131 is fixed on one side of the inner gantry 13 far away from the fork frame body 14. The top end of the piston rod of the front hydraulic cylinder 2 is fixed with a first fixing block 151, and the first driving assembly 15 comprises a first chain wheel 152 rotatably connected to two sides of the first fixing block 151 and a first chain 153 matched with the first chain wheel 152. The bottom end of the cylinder body of the front hydraulic cylinder 2 is fixedly connected with the inner gantry 13; one end of the first chain 153 is fixedly connected to the inner gantry beam 131, and the other end is fixed to the fork carriage body 14, so that the fork carriage body 14 is driven to slide on the inner gantry 13 by extending and retracting the piston rod of the front hydraulic cylinder 2.

An outer gantry beam 111 is fixed on one side of the outer gantry 11 far away from the fork frame body 14. The number of the rear hydraulic cylinders 3 is two, and the two rear hydraulic cylinders are respectively arranged on two sides of one side, close to the vehicle body, of the frame body 1. A second fixed block 161 is fixed on the piston rod of the rear hydraulic cylinder 3, and the second driving assembly 16 includes a second chain wheel 162 rotatably connected to one side of the two second fixed blocks 161 close to each other and a second chain 163 engaged with the second chain wheel 162. The second chain wheel 162 is positioned on one side of the frame body 1 close to the vehicle body. The cylinder body of the rear hydraulic cylinder 3 is fixed on the outer gantry 11, the side edge of the second fixing block 161 is fixed with the middle gantry 12, one end of the second chain 163 is fixedly connected on the outer gantry 11, the other end of the second chain is fixedly connected on the inner gantry 13, and the middle gantry 12 and the inner gantry 13 are driven to slide on the outer gantry 11 and the middle gantry 12 by the extension and retraction of the piston rod of the rear hydraulic cylinder 3.

Referring to fig. 1 and 2, an oil outlet 31 is fixed at the top end of the cylinder body of the rear hydraulic cylinder 3. The oil return pipeline 4 comprises a first oil return pipe 41 and a second oil return pipe 42 respectively connected with the oil outlets 31 of the two rear hydraulic cylinders 3, and a three-way pipe 43 connected with the first oil return pipe 41 and the second oil return pipe 42. The junction of the first oil return pipe 41 and the second oil return pipe is located on one side of the frame body 1 (the side close to the triple oil circuit 6). The first oil return pipe 41 is in an L shape, the vertical part of the first oil return pipe is downward along the rear hydraulic cylinder 3, and the horizontal part of the first oil return pipe passes through the outer gantry beam 111; the second scavenge pipe 42 runs directly down the rear cylinder 3. And a nylon cable tie 32 for limiting and fixing a pipeline is fixed on the rear hydraulic cylinder 3, and the first oil return pipe 41 and the second oil return pipe 42 are fixed on the rear hydraulic cylinder 3 by the nylon cable tie 32. The three-way pipe 43 is connected with the oil tank through an oil pipe. The frame body 1 is further provided with a pipe clamp 17 (a part of the pipe clamp is not shown in the figure) for fixing an oil pipe.

The pulley mechanism 8 includes a guide pulley 81 provided on one side of the second sprocket 162 (near the triple oil path 6), a first pulley assembly 82 and a second pulley assembly 83 provided above the second sprocket 162, and a third pulley assembly 84 provided at the top end of the front hydraulic cylinder 2. The number of the guide wheels 81 is one and the guide wheels are rotatably connected to the second fixing block 161.

The main oil path 5 includes a four-way valve 51 fixed to the outer gantry beam 111, a speed limit valve 52 communicated with a bottom end of the four-way valve 51, a first oil inlet pipe 53 and a second oil inlet pipe 54 communicated with both sides of the four-way valve 51, and a front hydraulic cylinder oil inlet pipe 55 communicated with a top end of the four-way valve 51. The speed limiting valve 52 is connected with the multi-way valve through an oil pipe.

The four-way valve 51 is positioned on one side of the outer gantry beam 111 close to the triple oil circuit 6. The first oil inlet pipe 53 and the second oil inlet pipe 54 are connected to the bottom ends of the cylinder bodies of the two rear hydraulic cylinders 3, respectively, to supply oil to the rear hydraulic cylinders 3. The second inlet pipe 54 is L-shaped in its tendency to move up the vertical portion along the rear cylinder 3 and to move through the horizontal portion below the outer mast cross-member 111.

The front hydraulic cylinder inlet pipe 55 is connected to the cylinder body of the front hydraulic cylinder 2 via a guide pulley 81, and supplies oil to the front hydraulic cylinder 2.

The function and tendency of the triple oil path 6 and the quadruple oil path 7 are the same, and one of them is used for explanation. The quadruple oil path 7 includes an oil path pipe 63, a first pipe joint assembly 61 communicated with one end of the oil path pipe 63 close to the vehicle body, and a second pipe joint assembly 62 communicated with one end of the oil path pipe 63 far from the vehicle body. The first pipe joint assembly 61 is connected with the multi-way valve through a rubber pipe; the second pipe joint component is connected with the accessory through a rubber pipe. A first limiting block 18 for limiting the trend of the oil line pipe 63 is fixed on the inner gantry 13, and a second limiting block 19 for limiting the trend of the oil line pipe 63 is fixed on the inner gantry beam 131. The number of the oil path pipes 63 is two, one is responsible for oil inlet, and the other is responsible for oil outlet.

A connecting plate 112 is fixed on the outer gantry beam 111, and the first pipe joint assembly 61 is fixed by the connecting plate 112; be fixed with connecting block 113 on the outer portal 11, be provided with on the connecting block 113 and carry out the pipe clamp 17 fixed to oil pipe 63, first loose pulley assembly 82 is walked around to oil pipe 63, and including the portal lower extreme change the trend of oil pipe 63 through first stopper 18, walk around the rear side of preceding pneumatic cylinder 2 (the one side that is close to the automobile body), spacing through second stopper 19, walk around third loose pulley assembly 84, the front side of pneumatic cylinder 2 is fixed on fork frame body 14 in the front. The oil line pipe 63 is installed behind the inner gantry 13 and the front hydraulic cylinder 2, and does not affect the view between the front hydraulic cylinder 2 and the inner gantry 13 on the side where the quadruple oil line 7 is arranged.

In the same way, the layout of the triple oil circuit 6 is the same, and the view between the front hydraulic cylinder 2 and the inner door frame 13 arranged on one side of the triple oil circuit 6 is not influenced.

Referring to fig. 1 and 3, the first pulley assembly 82 and the second pulley assembly 83 are alternatively described. The first pulley assembly 82 includes a connection plate 821 slidably connected to the second fixing block 161, a plurality of pulleys 822 rotatably connected to the connection plate 821, support blocks 823 fixed to both sides of the second fixing block 161, a fixing rod 824 vertically fixed to the support blocks 823, a spring 825 sleeved on the fixing rod 824, a slider 826 fixed to one side of the connection plate 821 close to the second fixing block 161 and slidably connected to the fixing rod 824, and a stopper 827 fixed to both sides of the second fixing block 161 and located below the support blocks 823.

The connecting plate 821 is vertically arranged, and the supporting block 823, the sliding block 826 and the limiting block 827 are perpendicular to the connecting plate 821. The pulley 822 is arranged in a circumferential direction of the second sprocket 162, and a rotation shaft of the pulley 822 is perpendicular to the connection plate 821. The two ends of the spring 825 respectively abut against the supporting block 823 and the slider 826, and drive the slider 826 to move in a direction away from the supporting block 823. The deformation of the spring 825 provides a cushion stroke and a reserve amount for the variation of the oil passage pipe 63, and can reduce the excessive pulling of the oil passage pipe 63.

Referring to fig. 1 and 4, the third pulley assembly 84 includes a support plate 841 fixed to a top end of the first fixing block 151, a support frame 842 fixed to a top end of the support plate 841 by bolts, and a plurality of pulleys 822 rotatably coupled to the support frame 842. The cross section of the support 842 is approximately N-shaped, the rotating shafts of the pulleys 822 are distributed in an arc shape, and a gap for the pipeline to pass through exists between the top end of the pulley 822 and the support 842.

The distance between the rear hydraulic cylinders 3 located on two sides of the frame body 1 is increased as much as possible by the aid of the chain wheels and the pulleys which are longitudinally arranged, the second chain 163 is arranged on the rear side of the inner door frame 13 channel steel, the triple oil circuit 6 and the quadruple oil circuit 7 are directly embedded into the inner door frame 13 channel steel, the first pulley component 82 and the second pulley component 83 are embedded into the upper portion of the second chain wheel 162, and accordingly the effect that the visual field is not reduced when the triple oil circuit 6 and the quadruple oil circuit 7 are installed can be achieved.

The embodiments of the present invention are preferred embodiments of the present invention, and the scope of the present invention is not limited by these embodiments, so: all equivalent changes made according to the structure, shape and principle of the invention are covered by the protection scope of the invention.

Claims

1. An oil circuit system of a forklift gantry comprises a frame body (1), a front hydraulic cylinder (2) arranged on the frame body (1), a rear hydraulic cylinder (3) arranged on the frame body (1), a main oil circuit (5) for providing power for the front hydraulic cylinder (2) and the rear hydraulic cylinder (3), a triple oil circuit (6) and a quadruple oil circuit (7) for providing power for accessories and positioned at two sides of the frame body (1), and a pulley mechanism (8) arranged on the frame body (1) for providing support for the oil circuits; the frame body (1) comprises an outer door frame (11), a middle door frame (12), an inner door frame (13), a fork frame body (14) connected with the inner door frame (13) in a sliding mode, a first driving assembly (15), a second driving assembly (16) and a plurality of pipe clamps (17) fixed on the frame body (1) and the rear hydraulic cylinder (3); an inner gantry beam (131) is fixed on one side of the inner gantry (13) far away from the fork frame body (14), and an outer gantry beam (111) is fixed on one side of the outer gantry (11) far away from the fork frame body (14); a first fixing block (151) is fixed at the top end of a piston rod of the front hydraulic cylinder (2), and the first driving assembly (15) comprises a first chain wheel (152) which is rotatably connected to two sides of the first fixing block (151) and a first chain (153) matched with the first chain wheel (152); the number of the rear hydraulic cylinders (3) is two, and the two rear hydraulic cylinders are respectively arranged on two sides of one side, close to the vehicle body, of the frame body (1); be fixed with second fixed block (161) on the piston rod of back pneumatic cylinder (3), second drive assembly (16) including rotate connect two second fixed blocks (161) be close to second sprocket (162) and with second sprocket (162) complex second chain (163) of one side each other, its characterized in that: the pulley mechanism (8) comprises a guide wheel (81) arranged on one side of one of the second chain wheels (162), a first pulley assembly (82) and a second pulley assembly (83) which are respectively arranged above the two second chain wheels (162), and a third pulley assembly (84) arranged at the top end of the front hydraulic cylinder (2), wherein the number of the guide wheels (81) is one, and the guide wheels are rotatably connected with the second fixed block (161); the second chain wheel (162) is arranged on one side of the frame body (1) close to the vehicle body; the triple oil circuit (6) and the quadruple oil circuit (7) respectively comprise an oil circuit pipe (63), a first pipe joint assembly (61) communicated with one end, close to the vehicle body, of the oil circuit pipe (63) and a second pipe joint assembly (62) communicated with one end, far away from the vehicle body, of the oil circuit pipe (63); the first pipe joint assembly (61) is fixed on an outer gantry beam (111), the oil pipeline pipe (63) is installed on an outer gantry (11) through a pipe clamp (17), bypasses a first pulley assembly (82), bypasses one side, close to a vehicle body, of the front hydraulic cylinder (2), and then bypasses a third pulley assembly (84), and is fixed on a fork frame body (14) on one side, far away from the vehicle body, of the front hydraulic cylinder (2); the main oil way (5) comprises a four-way valve (51) fixed on an outer gantry beam (111), a speed-limiting valve (52) communicated with the bottom end of the four-way valve (51), a first oil inlet pipe (53) and a second oil inlet pipe (54) communicated with two sides of the four-way valve (51) and a front hydraulic cylinder oil inlet pipe (55) communicated with the top end of the four-way valve (51); the front hydraulic cylinder oil inlet pipe (55) is connected to the cylinder body of the front hydraulic cylinder (2) through a guide wheel (81).

2. The forklift mast oil circuit system of claim 1, wherein: an oil outlet (31) is fixed at the top end of the cylinder body of the rear hydraulic cylinder (3); an oil return pipeline (4) is arranged on the oil outlet (31); the oil return pipeline (4) comprises a first oil return pipe (41) and a second oil return pipe (42) which are respectively connected with the oil outlets (31) of the two rear hydraulic cylinders (3) and a three-way pipe (43) connected with the first oil return pipe (41) and the second oil return pipe; the junction of the first oil return pipe (41) and the second oil return pipe (42) is positioned on one side of the frame body (1); the first oil return pipe (41) is L-shaped in trend, the vertical part is downward along the rear hydraulic cylinder (3), and the horizontal part passes through the outer gantry beam (111); the second oil return pipe (42) directly goes down along the rear hydraulic cylinder (3).

3. The forklift mast oil circuit system of claim 1, wherein: the number of the triple oil circuit (6) and the quadruple oil circuit (7) is two, and the number of the oil circuit pipes (63) is two.

4. The forklift mast oil circuit system of claim 1, wherein: the first pulley assembly (82) and the second pulley assembly (83) are identical in structure and respectively comprise a connecting plate (821) connected with the second fixing block (161) in a sliding mode and a plurality of pulleys (822) connected with the connecting plate (821) in a rotating mode; the rotating shaft of the pulley (822) is perpendicular to the connecting plate (821), and the pulleys (822) are arranged along the circumferential direction of the second chain wheel (162).

5. The forklift mast oil circuit system of claim 4, wherein: the first pulley component (82) and the second pulley component (83) further comprise a supporting block (823) fixed on the side edge of the second fixing block (161), a fixing rod (824) vertically fixed on the supporting block (823), a sliding block (826) fixed on one side of the connecting plate (821) close to the second fixing block (161) and connected with the fixing rod (824) in a sliding mode, and an elastic piece driving the sliding block (826) to move in the direction away from the supporting block (823).

6. The forklift mast oil circuit system of claim 5, wherein: the side of second fixed block (161) still is fixed with stopper (827) that can with slider (826) butt, and stopper (827) are located the below of supporting shoe (823).