Forklift multi-way valve neutral position detection device and control method

Abstract

A forklift multi-way valve neutral position detection device comprises a multi-way valve body, and a plurality of valve rods arranged side by side are arranged on the multi-way valve body. The valve rod is sleeved with a switch support, and a ball pressing type microswitch is arranged on the side wall of the switch support. A ball is arranged at one end of the microswitch and makes contact with the valve rod, and a notch corresponding to the ball is formed in the valve rod. And when the valve rod is not in the neutral position state, the notch drives the ball to move, and the microswitch circuit is switched on. According to the control method, the position state of the valve rod of the multi-way valve is judged through the microswitch, and the hydraulic system is controlled.

Description

Technical Field

[0001] The invention relates to the technical field of forklift control, and mainly to a forklift multi-way valve mid-position detection device and a control method. Background Art

[0002] Forklifts are various wheeled transport vehicles that are used for loading, unloading, stacking and short-distance transportation of palletized goods. Based on operational safety requirements, after the operator returns to the normal operating position, the power operation from rest should only occur when activated from the neutral position. If the operator moves the operating lever when it is not in the normal operating position and suddenly returns to the operating position, if there is no neutral position recognition at this time, the hydraulic system will be triggered, causing the mast of the forklift to move, which may cause danger to people around the vehicle.

[0003] The invention patent with application publication number CN117699698A discloses a mid-position identification mechanism for a multi-way valve, a forklift and a control method for its operation, a sensor for emitting light from the mid-position identification mechanism for the multi-way valve and a plurality of light shielding members, wherein the sensor is fixedly mounted on one side of the multi-way valve, and the plurality of light shielding members are assembled one by one in the plurality of valve stems of the multi-way valve and are linked with the valve stems; a light-transmitting opening is provided on the light shielding member, and when the plurality of valve stems of the multi-way valve are all in the mid-position, the light-transmitting openings of the plurality of light shielding members are in the same straight line for the light of the sensor to pass through; when any valve stem of the multi-way valve is not in the mid-position, the light shielding member on the valve stem that is not in the mid-position blocks the light of the sensor and electrocutes the sensor. Summary of the invention

[0004] The existing technology mostly uses photoelectric sensors and light shielding parts to realize the mid-position detection of the multi-way valve. The installation of photoelectric sensors and light shielding parts requires a fixed bracket and a certain installation space. At the same time, there is a certain position accuracy requirement between the light-transmitting hole and the photoelectric sensor. Such a setting will occupy the upper space of the multi-way valve and the longer installation and debugging time in actual production, reducing production efficiency. The existing technology also has a design of using a micro switch for mid-position detection, but the micro switch is mostly located on the top of the multi-way valve. If the forklift is working in a harsh working condition, the vibration of the whole vehicle will cause the connector to loosen, and the pollution of high-temperature oil vapor and air dust will have a great impact on the accuracy of the sensor and the function of the micro switch.

[0005] In order to solve the above problems, the technical solution provided by the present invention is: a forklift multi-way valve mid-position detection device, including a multi-way valve body, on which a plurality of valve stems arranged side by side are arranged; a switch support is connected to the outer shell of the valve stem, and a ball-pressed micro switch is arranged on the side wall of the switch support; a ball is arranged at one end of the micro switch to contact the valve stem, and a notch corresponding to the ball is arranged on the valve stem; when the valve stem is not in the mid-position state, the notch drives the ball to move, and the micro switch circuit is turned on.

[0006] Specifically, the micro switch includes a ball disposed at a connection with the valve stem, a spring connected to the ball is disposed in the middle of the micro switch, and the other end of the spring is connected to the switch circuit.

[0007] Specifically, when the ball is displaced toward the middle of the micro switch, the spring is compressed and the switch circuit is connected.

[0008] Specifically, the valve stem is provided with a notch corresponding to the ball. When the valve stem is in the neutral state, the notch is at the position of the micro switch ball, and the ball does not move; when the valve stem is not in the neutral state, the notch moves up and down to drive the micro switch ball to move, compress the spring, and make the micro switch circuit electrically connected. The micro switch occupies a small volume, has the characteristics of simple installation and flexible spatial layout, does not require additional photoelectric sensors, does not occupy the upper space of the multi-way valve, does not require a long installation and debugging time in actual production, and reduces the misjudgment caused by interference from external environmental factors.

[0009] Specifically, the switch support is fixed to the multi-way valve body by bolts, and is sleeved outside the valve stem to seal the valve stem.

[0010] Specifically, a threaded sealing opening is provided on the side wall of the switch support, and the micro switch is inserted into the threaded sealing opening.

[0011] Specifically, the micro switch is fixed by plugging through the threaded sealing port of the switch support, and the end of the micro switch with the ball is inside the switch support and contacts the valve stem; an O-ring seal is provided at the threaded sealing port. The working process of the micro switch is carried out inside the switch support of the multi-way valve body, and is sealed by the O-ring, without contact with the outside air, and has good dust and water resistance, which effectively increases the service life of the micro switch; the micro switch is directly connected to the switch support through the thread, and the assembly is simple, without the need to manually adjust the relative position relationship between the valve stem and the ball in the micro switch, avoiding the phenomenon of the micro switch not being able to work due to improper assembly, effectively reducing the debugging time and improving production efficiency.

[0012] The present invention provides a control method for a forklift multi-way valve mid-position detection device, comprising the following steps: S1, determine whether the seat switch is turned on; S2. Use the forklift multi-way valve mid-position detection device to determine whether all valve stems of the multi-way valve are in the mid-position. If there is a valve stem that is not in the mid-position, return the valve stem to the mid-position; S3. Pull the valve stem and determine the position of the multi-way valve stem through the energized and de-energized states of the micro switch to operate the multi-way valve.

[0013] Specifically, the seat switch in S1 will only be turned on when the worker sits on the seat, and then the forklift multi-way valve can be operated. That is, this control method must ensure that the worker sits on the seat normally and the seat switch is turned on.

[0014] Specifically, in S3, the valve stem is first manipulated to energize the corresponding micro switch, and the corresponding attachment function of the forklift can be performed only after the micro switch is energized. For example, when the mast needs to be lowered, the corresponding valve stem is toggled, and the corresponding micro switch is energized, the lowering solenoid valve opens, and the mast can be lowered. When the mast needs to be tilted and the corresponding attachment function is completed, the corresponding valve stem is toggled, and the corresponding micro switch is energized, the main oil circuit solenoid valve opens, and the mast performs the corresponding action.

[0015] The beneficial effects of the present invention are as follows: a ball-type microswitch is applied and arranged at the valve stem on the lower side of the multi-way valve, thereby solving the problem of a large installation space required for the mid-position detection device; the microswitch and the valve stem are both located inside the switch support, the microswitch and the switch support are connected by threads, sealed with an O-ring, and are not in contact with the outside air, thus having good dust and water resistance, thereby effectively improving the service life of the microswitch and solving the problem of the influence of harsh working conditions such as high-temperature oil vapor and air dust pollution on the accuracy of the microswitch; at the same time, since the relative position of the valve stem and the microswitch is directly ensured by tightening the threads, no calibration or debugging is required, thereby effectively reducing the assembly time and improving the production efficiency; the microswitch occupies a small volume and has a flexible spatial layout. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 It is the overall structure diagram of the present invention.

[0017] Figure 2 This is a cross-sectional view of a micro switch.

[0018] Figure 3 It is an overall cross-sectional view of the present invention.

[0019] Figure 4 This is a flow chart of Embodiment 2 of the present invention.

[0020] Figure 5 This is a flowchart of Embodiment 3 of the present invention.

[0021] In the figure, 1 is the multi-way valve body, 2 is the micro switch, 4 is the O-ring, 5 is the ball, 6 is the switch support, 7 is the valve stem, 8 is the threaded sealing port, 9 is the bolt, and 10 is the recess. DETAILED DESCRIPTION

[0022] The present invention is described in detail below with reference to the accompanying drawings and embodiments.

[0023] Embodiment 1: A forklift multi-way valve mid-position detection device, such as Figure 1 and 3The multi-way valve body 1 is shown, on which are disposed a plurality of valve stems 7 arranged side by side; a switch support 6 is externally connected to the valve stem 7, on the side wall of which a micro switch 2 pressed by a ball 5 is disposed; a ball 5 is disposed at one end of the micro switch 2 to contact the valve stem 7, and a notch 10 corresponding to the ball 5 is disposed on the valve stem 7; when the valve stem 7 is not in a neutral position, the notch 10 drives the ball 5 to move, and the circuit of the micro switch 2 is turned on.

[0024] The micro switch 2 includes a ball 5 arranged at a connection with the valve stem 7. A spring connected to the ball 5 is arranged in the middle of the micro switch 2, and the other end of the spring is connected to the switch circuit.

[0025] When the ball 5 moves toward the middle of the micro switch 2, the spring is compressed and the switch circuit is connected.

[0026] The valve stem 7 is provided with a notch 10 corresponding to the ball 5. When the valve stem 7 is in the middle position, the notch 10 is at the position of the ball 5 of the micro switch 2, and the ball 5 does not move. When the valve stem 7 is not in the middle position, the notch 10 moves up and down to drive the ball 5 of the micro switch 2 to move, compress the spring, and make the circuit of the micro switch 2 electrically connected. The micro switch 2 occupies a small volume, has the characteristics of simple installation and flexible spatial layout, does not require additional photoelectric sensors, does not occupy the upper space of the multi-way valve, does not require a long installation and debugging time in actual production, and reduces the misjudgment caused by interference from external environmental factors.

[0027] like Figure 2 As shown, the micro switch 2 is a ball 5 push-type, normally open type, and the figure shows the initial state. The micro switch 2 is in a power-off and non-working state, and the circuit is disconnected. The ball 5 is a reciprocating part. The power-on and power-off control signals of the micro switch 2 circuit are generated by the displacement of the multi-way valve stem 7. After the valve stem 7 is displaced, the ball 5 is squeezed to produce a stroke, the spring is compressed, and the switch circuit is powered on; when the ball 5 is no longer under force, the spring resets, the ball 5 returns to the initial state, and the switch circuit is powered off and disconnected. The micro switch 2 can identify whether the valve stem 7 is in the middle position by the on and off state of the circuit. The micro switch 2 occupies a small volume and has the characteristics of simple installation and flexible spatial layout.

[0028] The switch support 6 is fixed to the multi-way valve body 1 by bolts 9 and sleeved on the outside of the valve stem 7 to seal the valve stem 7.

[0029] A threaded sealing opening 8 is provided on the side wall of the switch support 6 , and the micro switch 2 is inserted into the threaded sealing opening 8 .

[0030] like Figure 3The micro switch 2 shown is plugged and fixed through the threaded sealing port 8 of the switch support 6. One end of the micro switch 2 with the ball 5 is inside the switch support 6 and contacts the valve stem 7. The threaded sealing port 8 is provided with an O-ring 4 for sealing. The position of the threaded sealing port 8 corresponds to the position of the notch 10 of the valve stem 7 in the middle position. After the micro switch 2 is plugged and fixed through the threaded sealing port 8, the ball 5 of the micro switch 2 is just aligned with the notch 10 of the valve stem 7. The working process of the micro switch 2 is carried out inside the switch support 6 of the multi-way valve body 1, and is sealed by the O-ring 4, without contact with the outside air, and has good dust and water resistance, which effectively improves the service life of the micro switch 2 and solves the problem of the influence of harsh working conditions such as high temperature oil vapor and air dust pollution on the accuracy of the micro switch 2. The switch is directly connected to the switch support 6 through a thread, and the assembly is simple. There is no need to manually adjust the relative position relationship between the valve stem 7 and the ball 5 in the micro switch 2, which avoids the phenomenon of the micro switch 2 not being able to work due to improper assembly, effectively reduces the debugging time, and improves production efficiency.

[0031] The present invention provides a control method for a forklift multi-way valve mid-position detection device, comprising the following steps: S1. Determine whether the staff is sitting on the seat through the seat switch; S2. Determine whether all valve stems 7 of the multi-way valve are in the middle position by using the forklift multi-way valve middle position detection device. If there is a valve stem 7 that is not in the middle position, return the valve stem 7 to the middle position. S3, pull the valve stem 7, determine the position of the multi-way valve stem 7 by the energized and de-energized state of the micro switch 2, and operate the multi-way valve.

[0032] The seat switch in S1 will only be turned on when the worker sits on the seat, and the forklift multi-way valve can be operated at this time. That is, this control method must ensure that the worker sits on the seat normally and the seat switch is turned on.

[0033] The middle position of the multi-way valve in S2 means that the multiple valve stems 7 of the multi-way valve body 1 are all in the middle position, and at this time, the multiple micro switches 2 located at the multiple valve stems 7 are all in the power-off and non-working state; the multi-way valve is not in the middle position means that the multiple valve stems 7 of the multi-way valve body 1 are not in the middle position, that is, the micro switches 2 at the valve stems 7 are in the working state with power. When the multiple micro switches 2 are all in the power-off and non-working state, it is determined that the multi-way valve is in the middle position, and the hydraulic system can start working. When any of the multiple micro switches 2 is in the working state with power, it is determined that the multi-way valve is not in the middle position, and the hydraulic system cannot start working.

[0034] In S3, the valve stem 7 is first operated to energize the corresponding micro switch 2. Only after the micro switch 2 is energized can the corresponding attachment function of the forklift be performed.

[0035] Embodiment 2: A forklift multi-way valve mid-position detection device, such as Figure 1 and 3 As shown, it includes a multi-way valve body 1, on which are disposed a plurality of valve stems 7 arranged side by side; a switch support 6 is connected to the outer shell of the valve stem 7, on the side wall of the switch support 6 a micro switch 2 pressed by a ball 5 is disposed; a ball 5 is disposed at one end of the micro switch 2 to contact the valve stem 7, and a notch 10 corresponding to the ball 5 is disposed on the valve stem 7; when the valve stem 7 is not in a neutral state, the notch 10 drives the ball 5 to move, and the circuit of the micro switch 2 is turned on.

[0036] The micro switch 2 includes a ball 5 arranged at a connection with the valve stem 7. A spring connected to the ball 5 is arranged in the middle of the micro switch 2, and the other end of the spring is connected to the switch circuit.

[0037] When the ball 5 is displaced toward the middle of the micro switch 2, the spring is compressed and the switch circuit is connected.

[0038] like Figure 3 The valve stem 7 is provided with a notch 10 corresponding to the ball 5. When the valve stem 7 is in the middle position, the notch 10 is at the position of the ball 5 of the micro switch 2, and the ball 5 does not move. When the valve stem 7 is not in the middle position, the notch 10 moves up and down to drive the ball 5 of the micro switch 2 to move, compress the spring, and make the circuit of the micro switch 2 electrically connected. The micro switch 2 occupies a small volume, has the characteristics of simple installation and flexible spatial layout, does not require additional photoelectric sensors, does not occupy the upper space of the multi-way valve, does not require a long installation and debugging time in actual production, and reduces the misjudgment caused by interference from external environmental factors.

[0039] like Figure 2 As shown, the micro switch 2 is a ball 5 push-type, normally open type, and the figure shows the initial state. The micro switch 2 is in a power-off and non-working state, and the circuit is disconnected. The ball 5 is a reciprocating part. The power-on and power-off control signals of the micro switch 2 circuit are generated by the displacement of the multi-way valve stem 7. After the valve stem 7 is displaced, the ball 5 is squeezed to produce a stroke, the spring is compressed, and the switch circuit is powered on; when the ball 5 is no longer under force, the spring resets, the ball 5 returns to the initial state, and the switch circuit is powered off and disconnected. The micro switch 2 can identify whether the valve stem 7 is in the middle position by the on and off state of the circuit. The micro switch 2 occupies a small volume and has the characteristics of simple installation and flexible spatial layout.

[0040] The switch support 6 is fixed to the multi-way valve body 1 by bolts 9 and sleeved on the outside of the valve stem 7 to seal the valve stem 7.

[0041] A threaded sealing opening 8 is provided on the side wall of the switch support 6 , and the micro switch 2 is inserted into the threaded sealing opening 8 .

[0042] like Figure 3The micro switch 2 shown is plugged and fixed through the threaded sealing port 8 of the switch support 6. One end of the micro switch 2 with the ball 5 is inside the switch support 6 and contacts the valve stem 7. The threaded sealing port 8 is provided with an O-ring 4 for sealing. The position of the threaded sealing port 8 corresponds to the position of the notch 10 of the valve stem 7 in the middle position. After the micro switch 2 is plugged and fixed through the threaded sealing port 8, the ball 5 of the micro switch 2 is just aligned with the notch 10 of the valve stem 7. The working process of the micro switch 2 is carried out inside the switch support 6 of the multi-way valve body 1, and is sealed by the O-ring 4, without contact with the outside air, and has good dust and water resistance, which effectively improves the service life of the micro switch 2 and solves the problem of the influence of harsh working conditions such as high temperature oil vapor and air dust pollution on the accuracy of the micro switch 2. The switch is directly connected to the switch support 6 through a thread, and the assembly is simple. There is no need to manually adjust the relative position relationship between the valve stem 7 and the ball 5 in the micro switch 2, which avoids the phenomenon of the micro switch 2 not being able to work due to improper assembly, effectively reduces the debugging time, and improves production efficiency.

[0043] The present invention provides a control method for a forklift multi-way valve mid-position detection device, comprising the following steps: S1. Determine whether the staff is sitting on the seat through the seat switch; S2. Determine whether all valve stems 7 of the multi-way valve are in the middle position by using the forklift multi-way valve middle position detection device. If there is a valve stem 7 that is not in the middle position, return the valve stem 7 to the middle position. S3, pull the valve stem 7, determine the position of the multi-way valve stem 7 by the energized and de-energized state of the micro switch 2, and operate the multi-way valve.

[0044] The seat switch in S1 will only be turned on when the worker sits on the seat, and the forklift multi-way valve can be operated at this time. That is, this control method must ensure that the worker sits on the seat normally and the seat switch is turned on.

[0045] The middle position of the multi-way valve in S2 means that the multiple valve stems 7 of the multi-way valve body 1 are all in the middle position, and at this time, the multiple micro switches 2 located at the multiple valve stems 7 are all in the power-off and non-working state; the multi-way valve is not in the middle position means that the multiple valve stems 7 of the multi-way valve body 1 are not in the middle position, that is, the micro switches 2 at the valve stems 7 are in the working state with power. When the multiple micro switches 2 are all in the power-off and non-working state, it is determined that the multi-way valve is in the middle position, and the hydraulic system can start working. When any of the multiple micro switches 2 is in the working state with power, it is determined that the multi-way valve is not in the middle position, and the hydraulic system cannot start working.

[0046] In S3, the valve stem 7 is first operated to energize the corresponding micro switch 2. Only after the micro switch 2 is energized can the corresponding attachment function of the forklift be performed. For example, when the mast needs to be lowered, the corresponding valve stem 7 is turned, and after the corresponding micro switch 2 is energized, the lowering solenoid valve opens, and the mast can be lowered. When the mast needs to be tilted and the corresponding attachment function is completed, the corresponding valve stem 7 is turned, and after the corresponding micro switch 2 is energized, the main oil circuit solenoid valve opens, and the mast performs the corresponding action.

[0047] In this embodiment, the forklift multi-way valve mid-position detection device and control method are applied to an internal combustion forklift, such as Figure 4 The specific application process is as follows: A1, the seat switch is powered on. That is, this control method must ensure that the staff sits on the seat normally and the seat switch is turned on; A2, through the multi-way valve middle position detection device described in this embodiment, it is determined whether the multi-way valve is in the middle position. The middle position of the multi-way valve means that the multiple valve stems 7 of the multi-way valve body 1 are all in the middle position, and at this time, the multiple micro switches 2 located at the multiple valve stems 7 are all in the power-off and non-working state; the multi-way valve is not in the middle position means that the multiple valve stems 7 of the multi-way valve body 1 are not in the middle position. If the valve stem 7 is not in the middle position, the micro switch 2 at the valve stem 7 is in the power-on working state. When the multiple micro switches 2 are all in the power-off and non-working state, it is determined that the multi-way valve is in the middle position, and the hydraulic system can start working. When a micro switch 2 among the multiple micro switches 2 is in the power-on working state, it is determined that the multi-way valve is not in the middle position. For an internal combustion forklift, the descending solenoid valve and the main oil circuit solenoid valve are in the power-off state at this time, so the hydraulic system cannot start working, and the valve stem 7 must be returned to the middle to continue to determine the middle position of the multi-way valve. This detection device identifies the middle position state of the multi-way valve through the micro switch 2, has accurate detection and a relatively simple structural layout.

[0048] When it is determined that the multi-way valve is in the middle position and the hydraulic system can start working, enter step A3: pull the valve stem 7, and determine the position of the multi-way valve stem 7 through the energized and de-energized state of the micro switch 2 to realize the operation function of the multi-way valve. Example: When the mast needs to be lowered, the corresponding valve stem 7 is turned, and the corresponding micro switch 2 is energized, the lowering solenoid valve opens, and the mast can be lowered. When the mast needs to be tilted and the corresponding accessory function is completed, the corresponding valve stem 7 is turned, and the corresponding micro switch 2 is energized, the main oil circuit solenoid valve opens, and the mast realizes the corresponding action.

[0049] Embodiment 3: A forklift multi-way valve mid-position detection device comprises a multi-way valve body 1, on which are disposed a plurality of valve stems 7 arranged side by side; a switch support 6 is externally connected to the valve stem 7, on the side wall of which a micro switch 2 pressed by a ball 5 is disposed; a ball 5 is disposed at one end of the micro switch 2 to contact the valve stem 7, and a notch 10 corresponding to the ball 5 is disposed on the valve stem 7; when the valve stem 7 is not in the mid-position state, the notch 10 drives the ball 5 to move, and the circuit of the micro switch 2 is turned on.

[0050] The micro switch 2 includes a ball 5 arranged at a connection with the valve stem 7. A spring connected to the ball 5 is arranged in the middle of the micro switch 2, and the other end of the spring is connected to the switch circuit.

[0051] When the ball 5 is displaced toward the middle of the micro switch 2, the spring is compressed and the switch circuit is connected.

[0052] The valve stem 7 is provided with a notch 10 corresponding to the ball 5. When the valve stem 7 is in the middle position, the notch 10 is at the position of the ball 5 of the micro switch 2, and the ball 5 does not move. When the valve stem 7 is not in the middle position, the notch 10 moves up and down to drive the ball 5 of the micro switch 2 to move, compress the spring, and make the circuit of the micro switch 2 electrically connected. The micro switch 2 occupies a small volume, has the characteristics of simple installation and flexible spatial layout, does not require additional photoelectric sensors, does not occupy the upper space of the multi-way valve, does not require a long installation and debugging time in actual production, and reduces the misjudgment caused by interference from external environmental factors.

[0053] The switch support 6 is fixed to the multi-way valve body 1 by bolts 9 and sleeved on the outside of the valve stem 7 to seal the valve stem 7.

[0054] A threaded sealing opening 8 is provided on the side wall of the switch support 6 , and the micro switch 2 is inserted into the threaded sealing opening 8 .

[0055] The micro switch 2 is plugged and fixed through the threaded sealing port 8 of the switch support 6. One end of the micro switch 2 with the ball 5 is inside the switch support 6 and in contact with the valve stem 7. The threaded sealing port 8 is provided with an O-ring 4 for sealing. The position of the threaded sealing port 8 corresponds to the position of the notch 10 of the valve stem 7 in the middle position. After the micro switch 2 is plugged and fixed through the threaded sealing port 8, the ball 5 of the micro switch 2 is just aligned with the notch 10 of the valve stem 7. The working process of the micro switch 2 is carried out inside the switch support 6 of the multi-way valve body 1, and it is sealed by the O-ring 4, does not contact with the outside air, has good dustproof and waterproof properties, effectively improves the service life of the micro switch 2, and solves the influence of harsh working conditions such as high temperature oil vapor and air dust pollution on the accuracy of the micro switch 2. The micro switch 2 is directly connected to the switch support 6 through a thread, and the assembly is simple. There is no need to manually adjust the relative position relationship between the valve stem 7 and the ball 5 in the micro switch 2, which avoids the phenomenon of the micro switch 2 not being able to work due to improper assembly, effectively reduces the debugging time, and improves production efficiency.

[0056] The present invention provides a control method for a forklift multi-way valve mid-position detection device, comprising the following steps: S1. Determine whether the staff is sitting on the seat through the seat switch; S2. Determine whether all valve stems 7 of the multi-way valve are in the middle position by using the forklift multi-way valve middle position detection device. If there is a valve stem 7 that is not in the middle position, return the valve stem 7 to the middle position. S3, pull the valve stem 7, determine the position of the multi-way valve stem 7 by the energized and de-energized state of the micro switch 2, and operate the multi-way valve.

[0057] The seat switch in S1 will only be turned on when the worker sits on the seat, and the forklift multi-way valve can be operated at this time. That is, this control method must ensure that the worker sits on the seat normally and the seat switch is turned on.

[0058] In S3, the valve stem 7 is first operated to energize the corresponding micro switch 2. Only after the micro switch 2 is energized can the corresponding attachment function of the forklift be performed. For example, when the mast needs to be lowered, the corresponding valve stem 7 is turned, and after the corresponding micro switch 2 is energized, the lowering solenoid valve opens, and the mast can be lowered. When the mast needs to be tilted and the corresponding attachment function is completed, the corresponding valve stem 7 is turned, and after the corresponding micro switch 2 is energized, the main oil circuit solenoid valve opens, and the mast performs the corresponding action.

[0059] In this embodiment, the forklift multi-way valve mid-position detection device and control method are applied to an electric forklift, such as Figure 5 The specific application process is as follows: A1, the seat switch is powered on. That is, this control method must ensure that the staff sits on the seat normally and the seat switch is turned on; A2, when the multi-way valve is not in the middle position, the lifting link of the multi-way valve will cause the descending solenoid valve to lose power, and the tilt and attachment link will cause the motor to have no speed output; A3, the multiple micro switches 2 used in the mid-position detection device can also be used as the motor speed trigger device of the electric fork multi-way valve body 1. When the above-mentioned mid-position detection device is used, after the hydraulic system of step A2 can start working, step A3 is entered: the mid-position detection device continues the second detection to determine the action of a certain valve stem 7 in the multi-way valve body 1, such as descent determination, tilt determination, accessory function 1 determination, and accessory function 2 determination. The valve stem 7 and the micro switch 2 are in a one-to-one correspondence. When a valve stem 7 of the multi-way valve body 1 switches from the mid-position, the micro switch 2 installed at the corresponding position of the valve stem 7 enters the energized working state and transmits the signal to the motor controller. The motor controller determines which valve stem 7 is switched by determining which micro switch 2 is energized, and controls the motor to output different speeds to achieve the speed triggering of the multi-way valve body 1.

[0060] In particular, for lifting judgment, only the lifting potentiometer is needed to perform stroke detection and the gantry rises; for descending judgment, the micro switch 2 is not linked with the motor, but with the descending solenoid valve. When the micro switch 2 is in the energized working state, the descending solenoid valve is energized and opened, and the gantry can complete the descending action.

[0061] Although the present invention has been described in detail with reference to the aforementioned embodiments, it is still possible for those skilled in the art to modify the technical solutions described in the aforementioned embodiments, or to make equivalent substitutions for some of the technical features therein. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A forklift multi-way valve mid-position detection device, characterized in that: It includes a multi-way valve body, on which are arranged several valve stems arranged side by side; the valve stem outer shell is connected to a switch support, on the side wall of the switch support is a ball-pressed micro switch; a ball is provided at one end of the micro switch to contact the valve stem, and the valve stem is provided with a notch corresponding to the ball; when the valve stem is not in a neutral state, the notch drives the ball to move, and the micro switch circuit is turned on.

2. The forklift multi-way valve mid-position detection device according to claim 1, characterized in that: The micro switch comprises a ball disposed at a connection with the valve stem, a spring connected to the ball is disposed in the middle of the micro switch, and the other end of the spring is connected to a switch circuit.

3. The forklift multi-way valve mid-position detection device according to claim 1 or 2, characterized in that: When the ball moves toward the middle of the micro switch, the spring is compressed and the switch circuit is connected.

4. The forklift multi-way valve mid-position detection device according to claim 1, characterized in that: A notch corresponding to the ball is provided on the valve stem. When the valve stem is in the neutral position, the notch is at the position of the micro switch ball, and the ball does not move. When the valve stem is not in the neutral position, the up and down displacement of the notch drives the micro switch ball to move, compressing the spring and making the micro switch circuit electrically connected.

5. The forklift multi-way valve mid-position detection device according to claim 1, characterized in that: The switch support is fixed on the multi-way valve body by bolts and sleeved on the outside of the valve stem to seal the valve stem.

6. The forklift multi-way valve mid-position detection device according to claim 1, characterized in that: A threaded sealing opening is arranged on the side wall of the switch support, and the micro switch is plugged into the threaded sealing opening.

7. The forklift multi-way valve mid-position detection device according to claim 1 or 2, characterized in that: The micro switch is fixed by plugging through the threaded sealing port of the switch support. The end of the micro switch with the ball is located inside the switch support and contacts the valve stem. An O-ring seal is provided at the threaded sealing port.

8. A control method for a forklift multi-way valve mid-position detection device, characterized in that: The following steps are involved: S1, determine whether the seat switch is turned on; S2. Use the forklift multi-way valve mid-position detection device to determine whether all valve stems of the multi-way valve are in the mid-position. If there is a valve stem that is not in the mid-position, return the valve stem to the mid-position; S3. Pull the valve stem and determine the position of the multi-way valve stem through the energized and de-energized states of the micro switch to operate the multi-way valve.

9. The control method of the forklift multi-way valve mid-position detection device according to claim 8, characterized in that: The seat switch in S1 will only be turned on when the staff sits on the seat.

10. The control method of the forklift multi-way valve mid-position detection device according to claim 8, characterized in that: In S3, the valve stem is first operated to energize the corresponding micro switch, and then the hydraulic system performs the corresponding attachment function of the forklift.

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