A control method for front and back movement of a high-lift portal

Abstract

The application discloses a kind of high lifting gantry front and rear movement operation control method, including front and rear movement handle, operation control method includes the following steps: step 1, monitoring front and rear movement handle output signal;Step 2, if front and rear movement output signal C1 is in bM to M / 2 or M / 2 to (1-b)M, execute step 3, if front and rear movement output signal C1 is in 0 to bM or (1-b)M to M, execute step 4, wherein 0<b<0.5;Step 3, front and rear movement handle slowly moves, forklift gantry slowly moves;Step 4, front and rear movement handle quickly moves, forklift gantry quickly moves, the present application is by identifying gantry front and rear movement direction, control oil pump motor different speed, so that gantry front and rear movement speed is equal, improve gantry front movement speed, improve work efficiency, by identifying fork lifting height, different fork lifting height control different gantry front and rear movement speed and front and rear movement start acceleration, reduce high position operation shake, improve high position operation stability.

Description

Technical Field

[0001] This invention relates to forklift lifting systems, specifically a method for controlling the forward and backward movement of a high-lift mast. Background Technology

[0002] The acceleration and speed of the mast's forward and backward movement in existing high-lift forklifts are not related to the fork lifting height. When the forks are in a high position, the mast's forward and backward movement speed is high, resulting in a large starting acceleration and impact, causing significant vehicle sway and affecting the stability of high-lift operations. Furthermore, the mast's forward and backward movement speed is not related to the direction of movement. The rod-side and rodless chamber areas of the forward-moving cylinder are not equal, while the pump motor speed is the same, leading to a large difference in the mast's forward and backward movement speed, which affects operational efficiency. Summary of the Invention

[0003] The purpose of this invention is to provide a method for controlling the forward and backward movement of a high-lift gantry, so as to solve the problems mentioned in the background art.

[0004] To achieve the above objectives, the present invention provides the following technical solution:

[0005] A method for controlling the forward and backward movement of a high-lift gantry, characterized in that it includes a forward and backward movement handle, wherein the output signal C1 of the forward and backward movement handle is in the range of 0-M, and the operation control method includes the following steps:

[0006] Step 1: Monitor the output signal of the forward and backward movement handle;

[0007] Step 2: If the forward / backward shift output signal C1 is between bM and M / 2 or between M / 2 and (1-b)M, proceed to step 3. If the forward / backward shift output signal C1 is between 0 and bM or between (1-b)M and M, proceed to step 4, where 0 < b < 0.5.

[0008] Step 3: Slowly move the forklift mast forward and backward using the handle;

[0009] Step 4: Move the forklift mast quickly by moving the handle forward and backward.

[0010] As a further aspect of the present invention: the range of the output signal C1 of the forward and backward movement handle is 0-5V, M=5, b=0.4.

[0011] As a further embodiment of the present invention: the forklift mast is also provided with a mast forward movement direction switch, a mast backward movement direction switch, an oil pump motor controller, an oil pump motor, a hydraulic oil pump, a forward / backward movement proportional solenoid valve, a forward movement cylinder, and other components; when the forward / backward movement proportional solenoid valve solenoid m1 is energized, oil enters the rodless chamber of the forward movement cylinder, and the mast moves forward; when the forward / backward movement proportional solenoid valve solenoid m2 is energized, oil enters the rod chamber of the forward movement cylinder, and the mast moves backward.

[0012] As a further aspect of the present invention: step 3 includes the following steps:

[0013] Step 3.1: Monitor the fork lifting height signal C2. The range of the fork lifting height signal C2 is 0-N. The fork height H = Hmax * C2 / N, where: Hmax: the maximum lifting height of the fork of the high-level forklift, m;

[0014] Step 3.2: If H≤Hmax / 2, the forks are in the low position, proceed to step 3.3; if H>Hmax / 2, the forks are in the high position, proceed to step 3.4.

[0015] Step 3.3: By monitoring the changing trend of the forward and backward displacement output signal C1, if it decreases from large to small, the controller energizes the forward and backward displacement proportional valve solenoid m1, controlling the opening speed of the forward displacement proportional valve: V1 = Xmax * K1 / (t0 * K2), and controlling the acceleration time t1 of the oil pump motor: t1 = n1 * K2 * K3 / (a ​​* K4); if it increases from small to large, the controller energizes the forward and backward displacement proportional valve solenoid m2, controlling the opening speed of the backward displacement proportional valve: V3 = Xmax * K1 * K8 / (t0 * K2), and controlling the acceleration time t3 of the oil pump motor: t3 = n2 * K2 * K9 / (a ​​* K4).

[0016] Step 3.4: By monitoring the changing trend of the forward and backward displacement output signal C1, if it decreases from large to small, the controller energizes the forward and backward displacement proportional valve solenoid m1, controlling the opening speed of the forward displacement proportional valve: V5 = Xmax * K1 / (t0 * K10), and controlling the acceleration time of the oil pump motor t5 = n1 * K10 * K3 / (a ​​* K4); if it increases from small to large, the controller energizes the forward and backward displacement proportional valve solenoid m2, controlling the opening speed of the backward displacement proportional valve: V7 = Xmax * K1 * K8 / (t0 * K10), and controlling the acceleration time of the oil pump motor t7 = n2 * K10 * K9 / (a ​​* K4).

[0017] in:

[0018] V1, V5: Opening speed of the forward proportional solenoid valve, mm / s;

[0019] V3, V7: Opening speed of the rearward proportional solenoid valve, mm / s;

[0020] K1: The proportional valve opening speed coefficient related to the position of the forward and backward movement handle, K1 = 0.7;

[0021] K2: Low position influence coefficient of forks, K2 = 0.6;

[0022] K3: The forward movement speed coefficient of the gantry related to the position of the forward and backward movement handles, K3 = (2.5 - C1) / 2.5;

[0023] K4: The acceleration coefficient of the oil pump motor related to the position of the forward and backward movement handle, taken as K4 = 0.6;

[0024] K5: Unit conversion factor, K5 = 0.06;

[0025] K8: Front and rear displacement influence coefficient, K8 = A without pole / A with pole;

[0026] K9: The forward movement speed coefficient of the gantry related to the position of the forward and backward movement handles, K9 = (C1 - 2.5) / 2.5;

[0027] K10: Fork height influence coefficient, K10 = 1;

[0028] t0: Standard opening time of the forward proportional solenoid valve, in seconds;

[0029] t1: The acceleration time (s) of the oil pump motor speed from 0 to the target speed when the handle is pushed lightly;

[0030] t3: The acceleration time (s) of the oil pump motor speed from 0 to the target speed when the handle is pushed lightly;

[0031] t5: The acceleration time (s) of the oil pump motor speed from 0 to the target speed when the handle is pushed lightly;

[0032] t7: The acceleration time (s) of the oil pump motor speed from 0 to the target speed when the handle is pushed lightly;

[0033] Xmax: Maximum opening of the forward / backward proportional solenoid valve, in mm;

[0034] n1: Maximum speed of oil pump motor when the gantry moves forward, rpm, n1=V*A no rod / (q*η*K5);

[0035] n2: Maximum speed of oil pump motor when the gantry moves backward, rpm, n2=V*A_rod / (q*η*K5);

[0036] A. Rodless: Area of ​​the rodless cavity of the gantry forward / backward displacement cylinder, in mm 2 ;

[0037] A (with rod): Rod-type cavity area of ​​the gantry forward / backward displacement cylinder, mm 2 ;

[0038] V: Forward and backward movement speed of the gantry, mm / s;

[0039] q: Hydraulic pump displacement, ml / r;

[0040] η: Overall efficiency of the hydraulic oil pump;

[0041] a: Average acceleration of the oil pump motor, r / s 2 , take a=8r / s 2 .

[0042] As a further aspect of the present invention: step 4 includes the following steps:

[0043] Step 4.1: Monitor the fork lifting height signal C2. The range of the fork lifting height signal C2 is 0-N. The fork height H = Hmax * C2 / N, where: Hmax: the maximum lifting height of the fork of the high-level forklift, m;

[0044] Step 4.2: If H≤Hmax / 2, the forks are in the low position, proceed to step 4.3; if H>Hmax / 2, the forks are in the high position, proceed to step 4.4.

[0045] Step 4.3: By monitoring the changing trend of the forward and backward displacement output signal C1, if it decreases from large to small, the controller energizes the forward and backward displacement proportional valve solenoid m1, controlling the opening speed of the forward displacement proportional valve: V2 = Xmax * K6 / (t0 * K2), and controlling the acceleration time of the oil pump motor t2 = n1 * K2 * K3 / (a ​​* K7); if it increases from small to large, the controller energizes the forward and backward displacement proportional valve solenoid m2, controlling the opening speed of the backward displacement proportional valve: V4 = Xmax * K6 * K8 / (t0 * K2), and controlling the acceleration time of the oil pump motor t4 = n2 * K2 * K9 / (a ​​* K7).

[0046] Step 4.4: By monitoring the changing trend of the forward and backward displacement output signal C1, if it decreases from large to small, the controller energizes the forward and backward displacement proportional valve solenoid m1, controlling the opening speed of the forward displacement proportional valve: V6 = Xmax * K6 / (t0 * K10), and controlling the acceleration time of the oil pump motor t6 = n1 * K10 * K3 / (a ​​* K7); if it increases from small to large, the controller energizes the forward and backward displacement proportional valve solenoid m2, controlling the opening speed of the backward displacement proportional valve: V8 = Xmax * K6 * K8 / (t0 * K10), and controlling the acceleration time of the oil pump motor t8 = n2 * K2 * K9 / (a ​​* K10).

[0047] in:

[0048] V2, V6: Opening speed of the forward proportional solenoid valve, mm / s;

[0049] V4, V8: Opening speed of the rear proportional solenoid valve, mm / s;

[0050] K6: The proportional valve opening speed coefficient related to the position of the forward and backward movement handle, with K1 = 1;

[0051] K7: The acceleration coefficient of the oil pump motor related to the position of the forward and backward movement handle, take K7 = 1;

[0052] t2: The acceleration time (s) of the oil pump motor speed from 0 to the target speed when the handle is pushed hard;

[0053] t4: The acceleration time (s) of the oil pump motor speed from 0 to the target speed when the handle is pulled hard;

[0054] t6: The acceleration time (s) of the oil pump motor speed from 0 to the target speed when the handle is pushed hard;

[0055] t8: The acceleration time (s) of the oil pump motor speed from 0 to the target speed when the handle is pulled hard.

[0056] As a further aspect of the present invention: the range of the fork lifting height signal C2 is 0-5V, the fork lifting height H is positively correlated with C2, 5V corresponds to the maximum lifting height Hmax of the forklift, and H = Hmax * C2 / 5.

[0057] Compared with the prior art, the beneficial effects of this invention are: This application identifies the forward and backward movement direction of the mast and controls different speeds of the oil pump motor to ensure equal forward and backward movement speeds of the mast, thereby increasing the mast's forward movement speed and improving operational efficiency. This application also identifies the fork lifting height and controls different forward and backward movement speeds and accelerations for different fork lifting heights, reducing swaying during high-level operations and improving stability during high-level operations. Detailed Implementation

[0058] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0059] In this embodiment of the invention, a method for controlling the forward and backward movement of a high-lift gantry includes a gantry forward and backward movement control system comprising a forward and backward movement handle, a gantry forward movement direction switch, a gantry backward movement direction switch, an oil pump motor controller, an oil pump motor, a hydraulic oil pump, a forward and backward movement proportional solenoid valve, a forward movement cylinder, and other components. When the solenoid m1 of the forward and backward movement proportional solenoid valve is energized, oil enters the rodless chamber of the forward movement cylinder, and the gantry moves forward. When the solenoid m2 of the forward and backward movement proportional solenoid valve is energized, oil enters the rod chamber of the forward movement cylinder, and the gantry moves backward.

[0060] The range of the forward and backward movement handle output signal C1 is 0-M, and the range of the forward and backward movement handle output signal C1 is 0-5V, M=5, b=0.4; the range of the fork lifting height signal C2 is 0-5V, the fork lifting height H is positively correlated with C2, 5V corresponds to the maximum lifting height Hmax of the forklift, H=Hmax*C2 / 5.

[0061] The operation control method includes the following steps:

[0062] Step 1: Monitor the output signal of the forward and backward movement handle;

[0063] Step 2: If the forward / backward shift output signal C1 is between bM and M / 2 or between M / 2 and (1-b)M, that is, 2≤C1<2.5 or 2.5<C1≤3, proceed to step 3. If the forward / backward shift output signal C1 is between 0 and bM or between (1-b)M and M, that is, 0≤C1<2 or 3<C1≤5, proceed to step 4, where 0<b<0.5.

[0064] Step 3: Slowly move the forklift mast forward and backward using the handle;

[0065] Step 3 includes the following steps:

[0066] Step 3.1: Monitor the fork lifting height signal C2. The range of the fork lifting height signal C2 is 0-N. The fork height H = Hmax * C2 / N, where: Hmax: the maximum lifting height of the fork of the high-level forklift, m;

[0067] Step 3.2: If H≤Hmax / 2, the forks are in the low position, proceed to step 3.3; if H>Hmax / 2, the forks are in the high position, proceed to step 3.4.

[0068] Step 3.3: By monitoring the changing trend of the forward and backward displacement output signal C1, if it decreases from large to small, the controller energizes the forward and backward displacement proportional valve solenoid m1, controlling the opening speed of the forward displacement proportional valve: V1 = Xmax * K1 / (t0 * K2), and controlling the acceleration time t1 of the oil pump motor: t1 = n1 * K2 * K3 / (a ​​* K4); if it increases from small to large, the controller energizes the forward and backward displacement proportional valve solenoid m2, controlling the opening speed of the backward displacement proportional valve: V3 = Xmax * K1 * K8 / (t0 * K2), and controlling the acceleration time t3 of the oil pump motor: t3 = n2 * K2 * K9 / (a ​​* K4).

[0069] Step 3.4: By monitoring the changing trend of the forward and backward displacement output signal C1, if it decreases from large to small, the controller energizes the forward and backward displacement proportional valve solenoid m1, controlling the opening speed of the forward displacement proportional valve: V5 = Xmax * K1 / (t0 * K10), and controlling the acceleration time of the oil pump motor t5 = n1 * K10 * K3 / (a ​​* K4); if it increases from small to large, the controller energizes the forward and backward displacement proportional valve solenoid m2, controlling the opening speed of the backward displacement proportional valve: V7 = Xmax * K1 * K8 / (t0 * K10), and controlling the acceleration time of the oil pump motor t7 = n2 * K10 * K9 / (a ​​* K4).

[0070] Step 4: Move the forklift mast quickly by moving the forklift handle forward and backward.

[0071] Step 4 includes the following steps:

[0072] Step 4.1: Monitor the fork lifting height signal C2. The range of the fork lifting height signal C2 is 0-N. The fork height H = Hmax * C2 / N, where: Hmax: the maximum lifting height of the fork of the high-level forklift, m;

[0073] Step 4.2: If H≤Hmax / 2, the forks are in the low position, proceed to step 4.3; if H>Hmax / 2, the forks are in the high position, proceed to step 4.4.

[0074] Step 4.3: By monitoring the changing trend of the forward and backward displacement output signal C1, if it decreases from large to small, the controller energizes the forward and backward displacement proportional valve solenoid m1, controlling the opening speed of the forward displacement proportional valve: V2 = Xmax * K6 / (t0 * K2), and controlling the acceleration time of the oil pump motor t2 = n1 * K2 * K3 / (a ​​* K7); if it increases from small to large, the controller energizes the forward and backward displacement proportional valve solenoid m2, controlling the opening speed of the backward displacement proportional valve: V4 = Xmax * K6 * K8 / (t0 * K2), and controlling the acceleration time of the oil pump motor t4 = n2 * K2 * K9 / (a ​​* K7).

[0075] Step 4.4: By monitoring the changing trend of the forward and backward displacement output signal C1, if it decreases from large to small, the controller energizes the forward and backward displacement proportional valve solenoid m1, controlling the opening speed of the forward displacement proportional valve: V6 = Xmax * K6 / (t0 * K10), and controlling the acceleration time of the oil pump motor t6 = n1 * K10 * K3 / (a ​​* K7); if it increases from small to large, the controller energizes the forward and backward displacement proportional valve solenoid m2, controlling the opening speed of the backward displacement proportional valve: V8 = Xmax * K6 * K8 / (t0 * K10), and controlling the acceleration time of the oil pump motor t8 = n2 * K2 * K9 / (a ​​* K10).

[0076] in

[0077] V: Forward and backward movement speed of the gantry, mm / s;

[0078] V1: Opening speed of the forward proportional solenoid valve, mm / s;

[0079] V2: Opening speed of the forward proportional solenoid valve, mm / s;

[0080] V3: Opening speed of the rear proportional solenoid valve, mm / s;

[0081] V4: Opening speed of the rear proportional solenoid valve, mm / s;

[0082] V5: Opening speed of the forward proportional solenoid valve, mm / s;

[0083] V6: Opening speed of the forward proportional solenoid valve, mm / s;

[0084] V7: Rear proportional solenoid valve opening speed, mm / s;

[0085] V8: Opening speed of the rearward proportional solenoid valve, mm / s;

[0086] K1: The proportional valve opening speed coefficient related to the position of the forward and backward movement handle, K1 = 0.7;

[0087] K2: Low position influence coefficient of forks, K2 = 0.6;

[0088] K3: The forward movement speed coefficient of the gantry related to the position of the forward and backward movement handle, K3 = (2.5 - C1) / 2.5; K4: The acceleration coefficient of the oil pump motor related to the position of the forward and backward movement handle, take K4 = 0.6;

[0089] K5: Unit conversion factor, K5 = 0.06;

[0090] K6: The proportional valve opening speed coefficient related to the position of the forward and backward movement handle, with K1 = 1;

[0091] K7: The acceleration coefficient of the oil pump motor related to the position of the forward and backward movement handle, take K7 = 1;

[0092] K8: Front and rear displacement influence coefficient, K8 = A without pole / A with pole;

[0093] K9: Mast forward movement speed coefficient related to the position of the forward and backward movement handle, K9 = (C1 - 2.5) / 2.5; K10: Fork height influence coefficient, take K10 = 1;

[0094] t0: Standard opening time of the forward proportional solenoid valve, in seconds;

[0095] t1: The acceleration time (s) of the oil pump motor speed from 0 to the target speed when the handle is pushed lightly;

[0096] t2: The acceleration time (s) of the oil pump motor speed from 0 to the target speed when the handle is pushed hard;

[0097] t3: The acceleration time (s) of the oil pump motor speed from 0 to the target speed when the handle is pushed lightly;

[0098] t4: The acceleration time (s) of the oil pump motor speed from 0 to the target speed when the handle is pulled hard. t5: The acceleration time (s) of the oil pump motor speed from 0 to the target speed when the handle is pushed lightly.

[0099] t6: The acceleration time (s) of the oil pump motor speed from 0 to the target speed when the handle is pushed hard;

[0100] t7: The acceleration time (s) of the oil pump motor speed from 0 to the target speed when the handle is pushed lightly;

[0101] t8: The acceleration time (s) of the oil pump motor speed from 0 to the target speed when the handle is pulled hard.

[0102] n1: Maximum speed of oil pump motor when the gantry moves forward, rpm, n1=V*A no rod / (q*η*K5);

[0103] A. Rodless: Area of ​​the rodless cavity of the gantry forward / backward displacement cylinder, in mm 2 ;

[0104] A (with rod): Rod-type cavity area of ​​the gantry forward / backward displacement cylinder, mm 2 ;

[0105] q: Hydraulic pump displacement, ml / r;

[0106] η: Overall efficiency of the hydraulic oil pump;

[0107] a: Average acceleration of the oil pump motor, r / s 2 , take a=8r / s 2 ;

[0108] n2: Maximum speed of oil pump motor when the gantry moves backward, rpm, n2=V*A with rod / (q*η*K5).

[0109] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above, and that the invention can be implemented in other specific forms without departing from the spirit or essential characteristics of the invention. Therefore, the embodiments should be considered in all respects as exemplary and non-limiting, and the scope of the invention is defined by the appended claims rather than the foregoing description. Thus, it is intended that all variations falling within the meaning and scope of equivalents of the claims be included within the present invention.

[0110] Furthermore, it should be understood that although this specification describes embodiments, not every embodiment contains only one independent technical solution. This narrative style is merely for clarity. Those skilled in the art should consider the specification as a whole, and the technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.

Claims

1. A method for controlling the forward and backward movement of a high-lift gantry, characterized in that, The system includes a forward / backward movement handle, wherein the output signal C1 of the forward / backward movement handle is in the range of 0-M, and the operation control method includes the following steps: Step 1: Monitor the output signal of the forward and backward movement handle; Step 2: If the forward / backward shift output signal C1 is between bM and M / 2 or between M / 2 and (1-b)M, execute step 3; if the forward / backward shift output signal C1 is between 0 and bM or between (1-b)M and M, execute step 4, where 0 < b < 0.

5. Step 3: Slowly move the forklift mast forward and backward using the handle; Step 4: Move the forklift mast quickly by moving the handle forward and backward; Step 3 includes the following steps: Step 3.1: Monitor the fork lifting height signal C2. The range of the fork lifting height signal C2 is 0-N. The fork height H = Hmax * C2 / N, where: Hmax: the maximum lifting height of the fork of the high-level operation forklift, m; Step 3.2: If H≤Hmax / 2, the forks are in the low position, proceed to step 3.3; if H>Hmax / 2, the forks are in the high position, proceed to step 3.

4. Step 3.3: By monitoring the changing trend of the forward and backward displacement output signal C1, if it decreases from large to small, the controller energizes the forward and backward displacement proportional valve solenoid m1, controlling the opening speed of the forward displacement proportional valve: V1=Xmax*K1 / (t0*K2), and controlling the acceleration time of the oil pump motor t1=n1*K2*K3 / (a*K4); if it increases from small to large, the controller energizes the forward and backward displacement proportional valve solenoid m2, controlling the opening speed of the backward displacement proportional valve: V3=Xmax*K1*K8 / (t0*K2), and controlling the acceleration time of the oil pump motor t3=n2*K2*K9 / (a*K4). Step 3.4: By monitoring the changing trend of the forward and backward displacement output signal C1, if it decreases from large to small, the controller energizes the forward and backward displacement proportional valve solenoid m1, controlling the opening speed of the forward displacement proportional valve: V5=Xmax*K1 / (t0*K10), and controlling the acceleration time of the oil pump motor t5=n1*K10*K3 / (a*K4); if it increases from small to large, the controller energizes the forward and backward displacement proportional valve solenoid m2, controlling the opening speed of the backward displacement proportional valve: V7=Xmax*K1*K8 / (t0*K10), and controlling the acceleration time of the oil pump motor t7=n2*K10*K9 / (a*K4). in: V1, V5: Opening speed of the forward proportional solenoid valve, mm / s; V3, V7: Opening speed of the rearward proportional solenoid valve, mm / s; K1: The proportional valve opening speed coefficient related to the position of the forward and backward movement handle, take K1=0.7; K2: Low position influence coefficient of forks, K2=0.6; K3: The forward movement speed coefficient of the gantry related to the position of the forward and backward movement handles, K3=(2.5-C1) / 2.5; K4: The acceleration coefficient of the oil pump motor related to the position of the forward and backward movement handle, taken as K4=0.6; K5: Unit conversion factor, K5=0.06; K8: Front and rear displacement influence coefficient, K8 = A without pole / A with pole; K9: The forward movement speed coefficient of the gantry related to the position of the forward and backward movement handles, K9=(C1-2.5) / 2.5; K10: Fork height influence coefficient, K10=1; t0: Standard opening time of the forward proportional solenoid valve, in seconds; t1: The acceleration time (s) of the oil pump motor speed from 0 to the target speed when the handle is pushed lightly; t3: The acceleration time (s) of the oil pump motor speed from 0 to the target speed when the handle is pushed lightly; t5: The acceleration time (s) of the oil pump motor speed from 0 to the target speed when the handle is pushed lightly; t7: The acceleration time (s) of the oil pump motor speed from 0 to the target speed when the handle is pushed lightly; Xmax: Maximum opening of the forward / backward proportional solenoid valve, in mm; n1: Maximum speed of oil pump motor when the gantry moves forward, rpm, n1=V*A no rod / (q*η*K5). n2: Maximum speed of oil pump motor when the gantry moves backward, rpm, n2=V*A_rod / (q*η*K5). A. Rodless: Area of ​​the rodless cavity of the gantry forward / backward displacement cylinder, in mm 2 ; A (with rod): Rod-type cavity area of ​​the gantry forward / backward displacement cylinder, mm 2 ; V: Forward and backward movement speed of the gantry, mm / s; q: Hydraulic pump displacement, ml / r; η: Overall efficiency of the hydraulic oil pump; a: Average acceleration of the oil pump motor, r / s ２ , take a=8r / s ２ .

2. The method for controlling the forward and backward movement of a high-lift gantry according to claim 1, characterized in that, The range of the output signal C1 of the forward and backward movement handle is 0-5V, M=5, b=0.

4.

3. The method for controlling the forward and backward movement of a high-lift gantry according to claim 1, characterized in that, The forklift mast is also equipped with a mast forward direction switch, a mast backward direction switch, an oil pump motor controller, an oil pump motor, a hydraulic oil pump, a forward / backward proportional solenoid valve, and a forward cylinder assembly. When the solenoid m1 of the forward / backward proportional solenoid valve is energized, oil enters the rodless chamber of the forward-moving cylinder, and the gantry moves forward; when the solenoid m2 of the forward / backward proportional solenoid valve is energized, oil enters the rod chamber of the forward-moving cylinder, and the gantry moves backward.

4. The method for controlling the forward and backward movement of a high-lift gantry according to claim 2, characterized in that, Step 4 includes the following steps: Step 4.1: Monitor the fork lifting height signal C2. The range of the fork lifting height signal C2 is 0-N. The fork height H = Hmax * C2 / N, where: Hmax: the maximum lifting height of the fork of the high-level operation forklift, m; Step 4.2: If H≤Hmax / 2, the forks are in the low position, proceed to step 4.3; if H>Hmax / 2, the forks are in the high position, proceed to step 4.

4. Step 4.3: By monitoring the changing trend of the forward and backward displacement output signal C1, if it decreases from large to small, the controller energizes the forward and backward displacement proportional valve solenoid m1, controlling the opening speed of the forward displacement proportional valve: V2=Xmax*K6 / (t0*K2), and controlling the acceleration time of the oil pump motor t2=n1*K2*K3 / (a*K7); if it increases from small to large, the controller energizes the forward and backward displacement proportional valve solenoid m2, controlling the opening speed of the backward displacement proportional valve: V4=Xmax*K6*K8 / (t0*K2), and controlling the acceleration time of the oil pump motor t4=n2*K2*K9 / (a*K7). Step 4.4: By monitoring the changing trend of the forward and backward displacement output signal C1, if it decreases from large to small, the controller energizes the forward and backward displacement proportional valve solenoid m1, controlling the opening speed of the forward displacement proportional valve: V6=Xmax*K6 / (t0*K10), and controlling the acceleration time of the oil pump motor t6=n1*K10*K3 / (a*K7); if it increases from small to large, the controller energizes the forward and backward displacement proportional valve solenoid m2, controlling the opening speed of the backward displacement proportional valve: V8=Xmax*K6*K8 / (t0*K10), and controlling the acceleration time of the oil pump motor t8=n2*K2*K9 / (a*K10). in: V2, V6: Opening speed of the forward proportional solenoid valve, mm / s; V4, V8: Opening speed of the rear proportional solenoid valve, mm / s; K6: The proportional valve opening speed coefficient related to the position of the forward and backward movement handle, with K1=1; K7: The acceleration coefficient of the oil pump motor related to the position of the forward and backward movement handle, take K7=1; t2: The acceleration time (s) of the oil pump motor speed from 0 to the target speed when the handle is pushed hard; t4: The acceleration time (s) of the oil pump motor speed from 0 to the target speed when the handle is pulled hard; t6: The acceleration time (s) of the oil pump motor speed from 0 to the target speed when the handle is pushed hard; t8: The acceleration time (s) of the oil pump motor speed from 0 to the target speed when the handle is pulled hard.

5. The method for controlling the forward and backward movement of a high-lift gantry according to claim 4, characterized in that, The range of the fork lifting height signal C2 is 0-5V. The fork lifting height H is positively correlated with C2. 5V corresponds to the maximum lifting height Hmax of the forklift. H=Hmax*C2 / 5.