CN-121974280-A - Control method and control system for lateral movement of fork of forward-drive forklift

CN121974280ACN 121974280 ACN121974280 ACN 121974280ACN-121974280-A

Abstract

The invention relates to the field of forklift control and discloses a fork lateral movement control method of a forward-driving forklift, which comprises the steps of acquiring a fork height signal, a load gravity signal and an operation command signal in real time, calculating to obtain a moment parameter for evaluating lateral movement stability, identifying the working condition category of the current lateral movement operation, and adaptively adjusting the control parameter of a lateral movement driving mechanism according to the judged working condition to execute lateral movement control matched with the working condition.

Inventors

ZHANG KEJUN
LIU JIAN
BI SHENG
ZHAO WEIGUO
XU JIAXIANG
Tao Yaman
XU LILI
ZHUO NALIN
LIU CHAOFAN
XU YIFAN

Assignees

安徽合力股份有限公司

Dates

Publication Date: 20260505
Application Date: 20260127

Claims (10)

1. The method for controlling the lateral movement of the fork of the forward-drive forklift is characterized by comprising the following steps of: Acquiring a fork height signal C1, a load gravity signal C2 and an operation instruction signal in real time; calculating a moment parameter N for evaluating side movement stability based on the fork height signal C1 and the load gravity signal C2; Identifying the working condition category of the current side-shifting operation according to the operation instruction signal and the moment parameter N, wherein the working condition category at least comprises a inching working condition, a normal working condition and a high-order heavy-load working condition; and according to the judged working condition, the control parameters of the side-shifting driving mechanism are adaptively adjusted so as to execute side-shifting control matched with the working condition.
2. The method for controlling lateral movement of a pallet fork of a forward-drive forklift according to claim 1, wherein the operation command signal includes: the analog quantity signal C3 of the side-shifting thumb switch is used for reflecting the change of the operation force and the intention; the forward push switch quantity signal B1 and the backward pull switch quantity signal B2 are used for indicating the operation direction gear of the side-shift thumb switch.
3. The method for controlling side shift of a pallet fork of a forward-drive forklift according to claim 1, The moment parameter N is the moment of the side-shifting friction force to the ground, and the calculation formula is as follows: N=F Side-shifting (h+h1) wherein F Side-shifting is side-shifting friction, h is fork lift height, h=c1 H max /10,H max is the maximum lifting height of the fork, and H1 is the distance between the upper surface of the fork and the center line of the side-shifting slide block; F Side-shifting =F (D+D1) u/L wherein F is the weight of the load and the component moving with the fork, f=p A/2, P is the front cylinder bottom pressure, p=c2 P max /10,P max is the maximum cylinder bottom pressure, A is the effective working area of the front cylinder, D is the load center distance, D1 is the distance from the fork surface to the side-shifting guide axis, u is the friction coefficient between the side-shifting slide block and the side-shifting frame, and L is the distance between the center of the side-shifting guide shaft and the center of the side-shifting slide block.
4. The method for controlling the lateral movement of the pallet fork of the forward-drive forklift according to claim 2, wherein the identifying the working condition category to which the current lateral movement operation belongs comprises: Confirming the side moving direction according to the forward pushing switching value signal B1 and the backward pulling switching value signal B2; Judging whether the current working condition is a inching working condition or a normal working condition according to different areas where the voltage value of the analog quantity signal C3 is located; and under the normal working condition, comparing the moment parameter N with a preset threshold N1, and further judging that the current working condition is the normal working condition or the high-order heavy-load working condition.
5. The method for controlling lateral movement of a pallet fork of a forward-drive forklift according to claim 4, wherein the inching condition is identified when the voltage value of the analog voltage signal C3 is in a first preset voltage interval, and when the voltage value of the analog voltage signal C3 is in a second preset voltage interval: if the moment parameter N is smaller than the preset threshold N1, identifying the moment parameter N as the normal working condition; and if the moment parameter N is greater than or equal to the preset threshold N1, identifying the moment parameter N as the high-order heavy-load working condition.
6. The method for controlling the lateral movement of the forks of a ride forward forklift according to claim 1, wherein said adjusting the control parameters of the lateral movement driving mechanism comprises: Judging that the current operation is a side shift start request or a side shift stop request according to the change trend of the operation command signal; According to different working condition types, when a side-shifting starting request is sent, controlling the rotating speed of an oil pump motor, the opening degree of a side-shifting electromagnetic reversing valve and controlling the opening time of the side-shifting electromagnetic reversing valve by adopting different time adjustment coefficients; When the side shifting stop request is sent, the oil pump motor is controlled to stop, the side shifting electromagnetic directional valve is controlled to be closed, and different time adjustment coefficients are adopted to control the closing time of the side shifting electromagnetic directional valve.
7. The method for controlling the lateral movement of the pallet fork of the forward-driving forklift according to claim 6, wherein when the forward-driving forklift is in the inching working condition, the lateral movement starting request controls the opening time of the lateral movement electromagnetic directional valve by using a time adjustment coefficient K1, and 1< K1<2.
8. The method for controlling the lateral movement of the pallet fork of the forward-drive forklift according to claim 6, wherein the lateral movement stopping request controls the closing time of the lateral movement electromagnetic directional valve by using a time adjustment coefficient K2 when the forward-drive forklift is in the inching working condition, wherein 1< K2<2.
9. The method according to claim 6, wherein the time adjustment coefficient is1 when in the normal operation, and the opening degree of the side-shifting electromagnetic directional valve is proportional to the voltage value of the analog voltage signal C3.
10. The method for controlling lateral movement of a fork of a forward-drive forklift according to claim 6, wherein when the forklift is in the high-level heavy-load working condition, the time adjustment coefficient is a dynamic coefficient K3, the value of the dynamic coefficient K3 is positively related to the fork lifting height h and the load gravity F, and the formula of the dynamic coefficient K3 is: K3=(M1 (h+D)+M2 h2)/ (M1 D+M2 h2) wherein M1 is a component moving along with the fork and a load mass, M2 is the mass of the vehicle body without a portal up-and-down moving component, D is a load center distance, and h2 is the gravity center height of the vehicle body without the portal up-and-down moving component.

Description

Control method and control system for lateral movement of fork of forward-drive forklift Technical Field The invention relates to the technical field of forklift control, in particular to a method and a system for controlling lateral movement of a fork of a forward-drive forklift. Background The fork side shifting function of the fork is used for carrying out transverse fine adjustment on the fork and the cargo borne by the fork, and is important for accurately taking and placing the cargo and improving the operation efficiency. However, the conventional forward-drive forklift has poor lateral movement mobility of the fork, lateral movement stopping deceleration is not related to the lifting height and the load weight of the fork, and high-position heavy-load lateral movement stopping impact of the fork is large, so that the vehicle shakes, and the operation safety is affected. Disclosure of Invention The invention aims to provide a control method and a control system for lateral shifting of a fork of a forward-drive forklift, which are used for solving the problems in the prior art, remarkably improving micro-motion operability, and adaptively adjusting a lateral shifting stopping process according to the height of the fork and the weight of a load, so that high-position heavy-load lateral shifting stopping impact is effectively restrained. The invention provides a method for controlling lateral movement of a fork of a forward-drive forklift, which comprises the following steps: Acquiring a fork height signal C1, a load gravity signal C2 and an operation instruction signal in real time; calculating a moment parameter N for evaluating side movement stability based on the fork height signal C1 and the load gravity signal C2; Identifying the working condition category of the current side-shifting operation according to the operation instruction signal and the moment parameter N, wherein the working condition category at least comprises a inching working condition, a normal working condition and a high-order heavy-load working condition; and according to the judged working condition, the control parameters of the side-shifting driving mechanism are adaptively adjusted so as to execute side-shifting control matched with the working condition. The method for controlling lateral movement of the fork of the forward-drive forklift as described above, wherein preferably, the operation command signal includes: the analog quantity signal C3 of the side-shifting thumb switch is used for reflecting the change of the operation force and the intention; the forward push switch quantity signal B1 and the backward pull switch quantity signal B2 are used for indicating the operation direction gear of the side-shift thumb switch. According to the control method for lateral movement of the fork of the forward-drive forklift, preferably, the torque parameter N is a torque of the lateral movement friction force to the ground, and the calculation formula is as follows: N=F Side-shifting (h+h1) wherein F Side-shifting is side-shifting friction, h is fork lift height, h=c1 H max/10,Hmax is the maximum lifting height of the fork, and H1 is the distance between the upper surface of the fork and the center line of the side-shifting slide block; F Side-shifting =F (D+D1) u/L wherein F is the weight of the load and the component moving with the fork, f=p A/2, P is the front cylinder bottom pressure, p=c2P max/10,Pmax is the maximum cylinder bottom pressure, A is the effective working area of the front cylinder, D is the load center distance, D1 is the distance from the fork surface to the side-shifting guide axis, u is the friction coefficient between the side-shifting slide block and the side-shifting frame, and L is the distance between the center of the side-shifting guide shaft and the center of the side-shifting slide block. According to the method for controlling lateral movement of the fork of the forward-drive forklift, preferably, the identifying the working condition category to which the current lateral movement operation belongs comprises the following steps: Confirming the side moving direction according to the forward pushing switching value signal B1 and the backward pulling switching value signal B2; Judging whether the current working condition is a inching working condition or a normal working condition according to different areas where the voltage value of the analog quantity signal C3 is located; and under the normal working condition, comparing the moment parameter N with a preset threshold N1, and further judging that the current working condition is the normal working condition or the high-order heavy-load working condition. As described above, in the method for controlling lateral movement of the fork of the forward-drive forklift, it is preferable that the inching condition is identified when the voltage value of the analog voltage signal C3 is in the first preset voltage interval, and when the voltage value o