Well repair platform

Abstract

The invention relates to the technical field of well repair equipment, in particular to a well repair platform which comprises a well mouth platform, a moving trolley, a hanging ring, an auxiliary guide rail and a guide rail gripper, the moving trolley capable of moving left and right is arranged on the well mouth platform, the auxiliary guide rail is fixedly connected to the hanging ring, and the guide rail gripper used for gripping the auxiliary guide rail is arranged on the moving trolley. When the guide rail gripper grabs the auxiliary guide rail, the auxiliary guide rail can only move up and down relative to the guide rail gripper. The device is reasonable in structure, and through the arrangement of the device, when a pipe rod is lifted and lowered, an operator does not need to manually push a lifting ring to transversely move at the position of a well opening to complete lifting and hanging of an elevator, and the operation labor intensity and the operation risk of the operator are greatly reduced.

Description

Technical Field

[0001] The invention relates to the technical field of well repair equipment, in particular to a well repair platform. Background Art

[0002] During well repair operations, when raising and lowering the pipe rod, the pipe rod needs to be lifted by an elevator installed on the lifting ring. Since the pipe rod needs to pass through the opening slot on one side of the elevator to enter or exit the elevator, the lifting ring and the elevator need to be moved horizontally relative to the pipe rod when removing and hanging the lifting ring at the wellhead. Since the well repair platforms currently on the market cannot drive the lifting ring to move horizontally at the wellhead to remove and hang the elevator, the operation of removing and hanging the elevator is still done manually, which increases the operation risk and labor intensity of the operators. Summary of the Invention

[0003] The present invention provides a well repair platform, which overcomes the above-mentioned shortcomings of the prior art and can effectively solve the problem that in the existing well repair operation, when the lifting ring is removed at the wellhead, manual pushing is required to move the lifting ring horizontally relative to the pipe rod.

[0004] The technical solution of the present invention is achieved through the following measures: a well repair platform, including a wellhead platform, a mobile trolley, a lifting ring, an auxiliary guide rail and a guide rail grabber. The wellhead platform is provided with a mobile trolley that can move left and right, the lifting ring is fixedly connected to the auxiliary guide rail, and the mobile trolley is provided with a guide rail grabber for grabbing the auxiliary guide rail. When the guide rail grabber grabs the auxiliary guide rail, the auxiliary guide rail can only move up and down relative to the guide rail grabber.

[0005] The following are further optimizations and / or improvements to the above invention: The above-mentioned guide rail gripper may include an abutment plate that can abut against the auxiliary guide rail and a locking mechanism that can lock the abutment plate and the auxiliary guide rail together. When the abutment plate and the auxiliary guide rail are locked together by the locking mechanism, the auxiliary guide rail can only move up and down relative to the abutment plate.

[0006] The above-mentioned auxiliary guide rail can be a V-shaped guide rail with its length direction parallel to the vertical direction and its opening facing right. The right side of the auxiliary guide rail is fixedly connected together by a connecting rod and a hanging ring. The abutment plate is a V-shaped plate with its opening facing right and its right side can be fitted together with the left side of the auxiliary guide rail.

[0007] The above-mentioned locking mechanism may include a fixed shaft sleeve, a rotating shaft, a first connecting rod, a second connecting rod, a driving cylinder, a fixed shaft and a locking roller. The fixed shaft sleeve is fixedly connected to the right side surface of the abutment plate, and the rotating shaft is rotatably installed in the fixed shaft sleeve. The upper end of the rotating shaft is fixedly connected to the first connecting rod, and the fixed shaft is fixedly connected to the first connecting rod. A conical locking roller is rotatably installed on the fixed shaft, and the diameter of the locking roller gradually increases from one end of the fixed shaft close to the first connecting rod to the end of the fixed shaft away from the first connecting rod. The lower end of the rotating shaft is fixedly connected to the second connecting rod, and the cylinder body of the driving cylinder is installed on the moving trolley. The piston rod of the driving cylinder and the second connecting rod are hinged, and the locking roller can abut against the side of the auxiliary guide rail when the piston rod of the driving cylinder is extended to lock the auxiliary guide rail between the abutment plate and the locking roller.

[0008] The above-mentioned well repair platform may also include a controller, the mobile trolley includes a frame and a travel drive mechanism for driving the frame to move left and right, the travel drive mechanism includes a screw, a slider and a screw motor, the screw is rotatably installed on the well repair platform, the screw is provided with a slider that can slide left and right, the frame and the slider are fixedly connected, the output shaft of the screw motor is transmission-connected to the screw, and the screw motor is connected to the controller; there are position No. 1, position No. 2 and position No. 3 on the moving path of the mobile trolley from left to right, and a position No. 1 sensor, a position No. 2 sensor and a position No. 3 sensor are respectively provided on the well repair platform corresponding to position No. 1, position No. 2 and position No. 3, and the position No. 1 sensor, the position No. 2 sensor and the position No. 3 sensor are respectively connected to the controller; the driving cylinder is connected to the controller through an electromagnetic valve.

[0009] The lifting ring may be provided with a signal generator, the mobile trolley may be provided with a signal receiver, and the signal receiver is connected to the controller.

[0010] The above-mentioned auxiliary guide rail may be provided with a first magnetic bar, a second magnetic bar, and a third magnetic bar, which are staggered from top to bottom, the upper end of the second magnetic bar is higher than the lower end of the first magnetic bar, and the upper end of the third magnetic bar is higher than the lower end of the second magnetic bar. The abutment plate is provided with a first magnetic switch, a second magnetic switch, and a third magnetic switch, which are arranged one-to-one corresponding to the first magnetic bar, the second magnetic bar, and the third magnetic bar. The first magnetic switch, the second magnetic switch, and the third magnetic switch are arranged side by side front to back; the first magnetic switch, the second magnetic switch, and the third magnetic switch are respectively connected to the controller.

[0011] The present invention has a reasonable structure. Through the configuration of the present invention, when lifting and lowering pipe rods, there is no need for operators to manually push the lifting ring to move horizontally at the wellhead position to complete the removal and hanging of the lifting card, which greatly reduces the labor intensity and operation risks of the operators. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Attachment Figure 1 It is a schematic diagram of the main structure of the best embodiment of the present invention.

[0013] Attachment Figure 2 A perspective view of the best embodiment of the present invention.

[0014] Attachment Figure 3 It is a three-dimensional diagram of the local structure in the best embodiment of the present invention.

[0015] Attachment Figure 4 For attachment Figure 3 Enlarged structural diagram at point A in the middle.

[0016] Attachment Figure 5 Schematic diagram of the positional relationship between three magnetic switches and three magnetic strips when outputting different signals in the best embodiment of the present invention.

[0017] The codes in the accompanying drawings are: 1 for the wellhead platform, 2 for the lifting ring, 3 for the auxiliary guide rail, 4 for the abutment plate, 5 for the fixed sleeve, 6 for the rotating shaft, 7 for the first connecting rod, 8 for the second connecting rod, 9 for the driving cylinder, 10 for the fixed shaft, 11 for the locking roller, 12 for the frame, 13 for the screw rod, 14 for the slider, 15 for the first magnetic bar, 16 for the second magnetic bar, 17 for the third magnetic bar, 18 for the rotating elevator, 19 for the first magnetic switch, 20 for the second magnetic switch, and 21 for the third magnetic switch. DETAILED DESCRIPTION

[0018] The present invention is not limited to the following embodiments, and specific implementation methods can be determined based on the technical solutions of the present invention and actual conditions.

[0019] In the present invention, for the convenience of description, the relative position relationship of each component is described based on the Figure 1 For example, the positional relationships of front, back, up, down, left, and right are determined according to the layout directions of the drawings in the specification.

[0020] The present invention will be further described below in conjunction with the embodiments and accompanying drawings: As attached Figure 1-5 As shown, the well repair platform includes a wellhead platform 1, a mobile trolley, a lifting ring 2, an auxiliary guide rail 3 and a guide rail grabber. The wellhead platform 1 is provided with a mobile trolley that can move left and right, the lifting ring 2 is fixedly connected to the auxiliary guide rail 3, and the mobile trolley is provided with a guide rail grabber for grabbing the auxiliary guide rail 3. When the guide rail grabber grabs the auxiliary guide rail 3, the auxiliary guide rail 3 can only move up and down relative to the guide rail grabber.

[0021] During operation, the wellhead platform 1 is placed at the wellhead, the lifting ring 2 is installed on the big hook of the traveling block system, and the automatic rotary elevator 18 is installed on the lifting ring 2. When the pipe rod is lifted, the pipe rod is located in the wellhead, and the pneumatic slips at the wellhead lock the pipe rod. The driller controls the lifting ring 2 to fall. When the lifting ring 2 falls to a certain height, the trolley moves to the right to grab the auxiliary guide rail 3 on the lifting ring 2 through the guide rail gripper, and then the trolley moves to the left to drive the lifting ring 2 to move left so that the rotary elevator 18 moves to the left side of the wellhead. The lifting ring 2 continues to fall until the rotary elevator 18 is lower than the coupling at the upper end of the pipe rod, and the lock tongue of the rotary elevator 18 is controlled to open. The trolley moves right to hang the pipe rod into the rotary elevator 18, and then controls to close the lock tongue of the rotary elevator 18, thereby hanging the pipe rod on the rotary elevator 18; when lowering the pipe rod, after the pipe rod on the rotary elevator 18 is connected with the pipe rod in the wellhead, the driller controls the lifting ring 2 to fall. After the lifting ring 2 falls a certain distance, the trolley moves right to grab the auxiliary guide rail 3 on the lifting ring 2 through the guide rail gripper. Then, the lifting ring 2 continues to fall a certain distance, and then the pneumatic slips lock the pipe rod, and controls to open the lock tongue of the rotary elevator 18. The trolley moves left to drive the lifting ring 2 and the rotary elevator 18 to move left, thereby allowing the pipe rod to exit the rotary elevator 18.

[0022] Through the arrangement of the present application, when lifting and lowering the pipe rod, there is no need for the operator to manually push the lifting ring 2 to move horizontally to complete the lifting card removal at the wellhead position, which greatly reduces the labor intensity and operation risks of the operator.

[0023] The above embodiments may be further optimized and / or improved according to actual needs: As attached Figure 1-4 As shown, the guide rail gripper includes an abutting plate 4 that can abut against the auxiliary guide rail 3 and a locking mechanism that can lock the abutting plate 4 and the auxiliary guide rail 3 together. When the abutting plate 4 and the auxiliary guide rail 3 are locked together by the locking mechanism, the auxiliary guide rail 3 can only move up and down relative to the abutting plate 4. Therefore, when the guide rail gripper grasps the auxiliary guide rail 3, the auxiliary guide rail 3 can only move up and down relative to the guide rail gripper.

[0024] As attached Figure 1 As shown, the auxiliary guide rail 3 is a V-shaped guide rail with its length parallel to the vertical direction and its opening facing right. The right side of the auxiliary guide rail 3 is fixedly connected to the lifting ring 2 via a connecting rod. The abutment plate 4 is a V-shaped plate with its opening facing right, and its right side can be abutted against the left side of the auxiliary guide rail 3. Both the auxiliary guide rail 3 and the abutment plate 4 are V-shaped with their openings facing right. Therefore, when the auxiliary guide rail 3 and the abutment plate 4 are tightly abutted together under the locking operation of the locking mechanism, the auxiliary guide rail 3 and the abutment plate 4 can be prevented from shifting forward and backward.

[0025] As attached Figure 1-4As shown, the locking mechanism includes a fixed shaft 10 sleeve 5, a rotating shaft 6, a first connecting rod 7, a second connecting rod 8, a driving cylinder 9, a fixed shaft 10 and a locking roller 11. The fixed shaft 10 sleeve 5 is fixedly connected to the right side of the abutment plate 4. The rotating shaft 6 is rotatably installed in the fixed shaft 10 sleeve 5. The upper end of the rotating shaft 6 is fixedly connected to the first connecting rod 7. The fixed shaft 10 is fixedly connected to the first connecting rod 7. The fixed shaft 10 is rotatably installed on the fixed shaft 10. The conical locking roller 11 is locked. The diameter of the roller 11 gradually increases from the end of the fixed shaft 10 close to the first connecting rod 7 to the end of the fixed shaft 10 away from the first connecting rod 7. The lower end of the rotating shaft 6 is fixedly connected to the second connecting rod 8. The cylinder body of the driving cylinder 9 is installed on the moving trolley. The piston rod of the driving cylinder 9 is hinged to the second connecting rod 8. The locking roller 11 can abut against the side of the auxiliary guide rail 3 when the piston rod of the driving cylinder 9 is extended to lock the auxiliary guide rail 3 between the abutment plate 4 and the locking roller 11. After the abutment plate 4 and the auxiliary guide rail 3 are fitted together, the piston rod of the control driving cylinder 9 is extended, and the locking roller 11 rotates around the center line of the rotating shaft 6 in the direction close to the auxiliary guide rail 3, thereby pressing the auxiliary guide rail 3 between the locking roller 11 and the abutment plate 4. At this time, the auxiliary guide rail 3 can only move up and down relative to the abutment plate 4; and when the locking effect on the abutment plate 4 and the auxiliary guide rail 3 is to be released, the piston rod of the control driving cylinder 9 is retracted, and the locking roller 11 rotates around the center line of the rotating shaft 6 in the direction away from the auxiliary guide rail 3, thereby releasing the auxiliary guide rail 3.

[0026] Specifically, the well repair platform also includes a controller. The mobile carriage includes a frame 12 and a travel drive mechanism that drives the frame 12 left and right. The travel drive mechanism includes a screw 13, a slider 14, and a motor for the screw 13. The screw 13 is rotatably mounted on the well repair platform, and a slider 14 is mounted on the screw 13, which can slide left and right. The frame 12 and the slider 14 are fixedly connected. The output shaft of the motor for the screw 13 is in transmission connection with the screw 13, and the motor for the screw 13 is connected to the controller. The mobile carriage has positions 1, 2, and 3 along its travel path, from left to right. Position sensors 1, 2, and 3 are respectively provided on the well repair platform corresponding to positions 1, 2, and 3. These sensors are connected to the controller. The drive cylinder 9 is connected to the controller via a solenoid valve. The through-hole controller thus controls the movement of the mobile carriage and the drive cylinder 9.

[0027] Specifically, a signal generator is provided on the lifting ring 2, and a signal receiver is provided on the mobile carriage. The signal receiver is connected to the controller. When the lifting ring 2 falls to a certain height, the signal receiver on the mobile carriage receives a signal from the signal generator, and the mobile carriage begins to move right to grasp the auxiliary guide rail 3. Specifically, in this embodiment, the signal generator is an ultrasonic generator, and the signal receiver is an ultrasonic receiver.

[0028] As attached Figure 5 As shown, the auxiliary guide rail 3 is provided with a first magnetic bar 15, a second magnetic bar 16, and a third magnetic bar 17, which are staggered from bottom to top, and the upper end of the first magnetic bar 15 is higher than the lower end of the second magnetic bar 16, and the upper end of the second magnetic bar 16 is higher than the lower end of the third magnetic bar 17. The abutment plate 4 is provided with a first magnetic switch 19, a second magnetic switch 20, and a third magnetic switch 21, which are arranged one-to-one corresponding to the first magnetic bar 15, the second magnetic bar 16, and the third magnetic bar 17. The first magnetic switch 19, the second magnetic switch 20, and the third magnetic switch 21 are arranged side by side front to back; the first magnetic switch 19, the second magnetic switch 20, and the third magnetic switch 21 are respectively connected to the controller. The first magnetic switch 19, the second magnetic switch 20, and the third magnetic switch 21 are all reed switches. The first magnetic switch 19, the second magnetic switch 20, and the third magnetic switch 21 remain normally open and close when sensing a magnetic signal of corresponding strength. By setting the first magnetic bar 15, the second magnetic bar 16, the third magnetic bar 17, the first magnetic switch 19, the second magnetic switch 20, and the third magnetic switch 21, the controller can receive five different signals during the falling process of the auxiliary guide rail 3. The five signals are defined as 100, 110, 010, 011, and 001 in sequence. The 100 signal represents that the first magnetic switch 19 senses the magnetic signal of the first magnetic bar 15 and is in the closed state, and the second magnetic switch 20 and the third magnetic switch 21 are in the open state; the 110 signal represents that the first magnetic switch 19, the second magnetic switch 20, and the third magnetic switch 21 are in the open state. 20 respectively senses that the magnetic signals of the first magnetic strip 15 and the second magnetic strip 16 are in the closed state, and the third magnetic switch 21 is in the open state; the 010 signal represents that the second magnetic switch 20 senses that the magnetic signal of the second magnetic strip 16 is in the closed state, and the first magnetic switch 19 and the third magnetic switch 21 are in the open state; the 011 signal represents that the second magnetic switch 20 and the third magnetic switch 21 respectively sense that the magnetic signals of the second magnetic strip 16 and the third magnetic strip 17 are in the closed state, and the first magnetic switch 19 is in the open state; the 001 signal represents that the third magnetic switch 21 senses that the magnetic signal of the third magnetic strip 17 is in the closed state, and the first magnetic switch 19 and the second magnetic switch 20 are in the open state; thus, the controller can control the movement of the mobile trolley and the movement of the drive cylinder 9 according to the received signals, so as to realize the automated operation of picking up and hanging up the elevator.

[0029] The specific working process is: Pipe rod lifting operation: Initially, the mobile trolley is at position 1, the pipe rod is at the wellhead, the pneumatic slips at the wellhead lock the pipe rod, the lock tongue of the rotary elevator 18 is opened, and the driller controls the lifting ring 2 to fall. When the signal receiver receives the signal from the signal generator, the controller controls the mobile trolley to move right from position 1 to position 3, the abutment plate 4 is in contact with the auxiliary guide rail 3, the controller controls the piston rod of the drive cylinder 9 to extend, the locking mechanism locks the abutment plate 4 and the auxiliary guide rail 3 together, and the lifting ring 2 continues to fall. When the controller receives the 110 signal, the mobile trolley is controlled to move left to position 2, and the lifting ring 2 continues to fall. When the controller receives the 001 signal, the mobile trolley is controlled to move right to position 3, the lock tongue of the rotary elevator 18 is closed, the pneumatic slips release the pipe rod, the driller controls the lifting of the lifting ring 2, and the rotary elevator 18 lifts the pipe rod.

[0030] Rod lowering operation: Initially, the trolley is located at position 1. When the rod on the rotary elevator 18 is connected to the rod in the wellhead, the driller controls the lifting ring 2 to drop. When the signal receiver receives the signal from the signal generator, the controller controls the trolley to move right from position 1 to position 3. The abutment plate 4 is in contact with the auxiliary guide rail 3. The controller controls the piston rod of the driving cylinder 9 to extend. The locking mechanism locks the abutment plate 4 and the auxiliary guide rail 3 together. The lifting ring 2 continues to drop. When the controller receives the 011 signal, it controls the pneumatic slips in the wellhead to lock the rod. The lifting ring 2 continues to drop. When the controller receives the 001 signal, it controls the opening of the lock tongue of the rotary elevator 18 and controls the trolley to move left to position 2. The rod exits the rotary elevator 18.

[0031] The above technical features constitute the best embodiment of the present invention, which has strong adaptability and best implementation effect. Non-essential technical features can be added or removed according to actual needs to meet the requirements of different situations.

Claims

1. A well repair platform, characterized in that It includes a wellhead platform, a mobile trolley, a lifting ring, an auxiliary guide rail and a guide rail grabber. The wellhead platform is provided with a mobile trolley that can move left and right. The lifting ring is fixedly connected to the auxiliary guide rail. The mobile trolley is provided with a guide rail grabber for grabbing the auxiliary guide rail. When the guide rail grabber grabs the auxiliary guide rail, the auxiliary guide rail can only move up and down relative to the guide rail grabber.

2. The well repair platform according to claim 1, characterized in that The guide rail gripper includes an abutment plate that can abut against the auxiliary guide rail and a locking mechanism that can lock the abutment plate and the auxiliary guide rail together. When the abutment plate and the auxiliary guide rail are locked together by the locking mechanism, the auxiliary guide rail can only move up and down relative to the abutment plate.

3. The well repair platform according to claim 2, characterized in that The auxiliary guide rail is a V-shaped guide rail with its length direction parallel to the vertical direction and its opening facing right. The right side of the auxiliary guide rail is fixedly connected by a connecting rod and a lifting ring. The abutment plate is a V-shaped plate with its opening facing right and its right side can be fitted together with the left side of the auxiliary guide rail.

4. The well repair platform according to claim 3, characterized in that The locking mechanism includes a fixed shaft sleeve, a rotating shaft, a first connecting rod, a second connecting rod, a driving cylinder, a fixed shaft and a locking roller. The fixed shaft sleeve is fixedly connected to the right side surface of the abutment plate, and the rotating shaft is rotatably installed in the fixed shaft sleeve. The upper end of the rotating shaft is fixedly connected to the first connecting rod, and the fixed shaft is fixedly connected to the first connecting rod. A conical locking roller is rotatably installed on the fixed shaft, and the diameter of the locking roller gradually increases from one end of the fixed shaft close to the first connecting rod to the end of the fixed shaft away from the first connecting rod. The lower end of the rotating shaft is fixedly connected to the second connecting rod, and the cylinder body of the driving cylinder is installed on the mobile trolley. The piston rod of the driving cylinder is hinged to the second connecting rod, and the locking roller can abut against the side of the auxiliary guide rail when the piston rod of the driving cylinder is extended to lock the auxiliary guide rail between the abutment plate and the locking roller.

5. The well repair platform according to claim 1, 2 or 3, characterized in that The trolley further comprises a controller, wherein the trolley comprises a frame and a travel drive mechanism for driving the frame to move left and right, the travel drive mechanism comprises a screw, a slider and a screw motor, a screw is rotatably mounted on the well repair platform, a slider which can slide left and right is provided on the screw, the trolley and the slider are fixedly connected, the output shaft of the screw motor is transmission-connected to the screw, and the screw motor is connected to the controller; there are position No. 1, position No. 2 and position No. 3 on the moving path of the trolley from left to right, and a position No. 1 sensor, a position No. 2 sensor and a position No. 3 sensor are respectively provided on the well repair platforms corresponding to position No. 1, position No. 2 and position No. 3, and the position No. 1 sensor, the position No. 2 sensor and the position No. 3 sensor are respectively connected to the controller.

6. The well repair platform according to claim 4, characterized in that The trolley further comprises a controller, wherein the trolley comprises a frame and a travel drive mechanism for driving the frame to move left and right, the travel drive mechanism comprises a screw, a slider and a screw motor, a screw is rotatably mounted on the well repair platform, a slider which can slide left and right is provided on the screw, the frame and the slider are fixedly connected, the output shaft of the screw motor is transmission-connected to the screw, and the screw motor is connected to the controller; there are position No. 1, position No. 2 and position No. 3 on the moving path of the trolley from left to right, and a position No. 1 sensor, a position No. 2 sensor and a position No. 3 sensor are respectively provided on the well repair platform corresponding to position No. 1, position No. 2 and position No. 3, and the position No. 1 sensor, the position No. 2 sensor and the position No. 3 sensor are respectively connected to the controller; the driving cylinder is connected to the controller via an electromagnetic valve.

7. The well repair platform according to claim 5, characterized in that A signal generator is provided on the lifting ring, a signal receiver is provided on the moving trolley, and the signal receiver is connected to the controller.

8. The well repair platform according to claim 6, characterized in that A signal generator is provided on the lifting ring, a signal receiver is provided on the moving trolley, and the signal receiver is connected to the controller.

9. The well repair platform according to claim 5, characterized in that The auxiliary guide rail is provided with a first magnetic bar, a second magnetic bar, and a third magnetic bar, which are staggered from top to bottom. The upper end of the second magnetic bar is higher than the lower end of the first magnetic bar, and the upper end of the third magnetic bar is higher than the lower end of the second magnetic bar. The abutment plate is provided with a first magnetic switch, a second magnetic switch, and a third magnetic switch, which are arranged one-to-one corresponding to the first magnetic bar, the second magnetic bar, and the third magnetic bar. The first magnetic switch, the second magnetic switch, and the third magnetic switch are arranged side by side front to back; the first magnetic switch, the second magnetic switch, and the third magnetic switch are respectively connected to the controller.

10. The well repair platform according to claim 6, 7 or 8, characterized in that The auxiliary guide rail is provided with a first magnetic bar, a second magnetic bar, and a third magnetic bar, which are staggered from top to bottom. The upper end of the second magnetic bar is higher than the lower end of the first magnetic bar, and the upper end of the third magnetic bar is higher than the lower end of the second magnetic bar. The abutment plate is provided with a first magnetic switch, a second magnetic switch, and a third magnetic switch, which are arranged one-to-one corresponding to the first magnetic bar, the second magnetic bar, and the third magnetic bar. The first magnetic switch, the second magnetic switch, and the third magnetic switch are arranged side by side front to back; the first magnetic switch, the second magnetic switch, and the third magnetic switch are respectively connected to the controller.

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