Control circuit of garbage truck with detachable compartment
By designing a control circuit for a detachable garbage truck, the problem of not detecting whether the L-arm extension and retraction and the boom lifting are in place in the existing technology has been solved. The design of a control circuit for a detachable garbage truck has achieved detection and interlocking control of the L-arm extension and retraction and the boom lifting, avoiding safety accidents caused by human error and ensuring the safety of garbage truck operation.
Patent Information
- Application Number
- CN202423197514.9
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-12-24
- Publication Date
- 2025-12-05
- Estimated Expiration
- 2034-12-24
AI Technical Summary
Existing detachable garbage trucks lack detection for whether the L-arm extension and retraction and the boom lifting are in place, and the actions are not interlocked, which can easily lead to safety accidents. Furthermore, when hooking or unloading operations are performed before the L-arm or boom has reached the designated position, it may cause a change in the center of gravity of the entire vehicle, leading to the safety hazard of side or rear rollover.
A control circuit for a detachable garbage truck was designed. Through the combination of execution circuit and control circuit, including multiple control branches and relays, the detection and interlocking control of the L-arm extension and retraction and the boom lifting are realized to ensure that the next operation is carried out only after the action is in the appropriate position.
The patented design has been applied to the field of environmental pollution prevention and control technology, specifically involving the control circuit of a detachable garbage truck, and applied to the field of mechanical and electrical control technology, especially the control circuit of a detachable garbage truck.
Smart Images
Figure CN223632272U_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The utility model relates to mechanical electrical control technical field especially relates to a control circuit of detachable garbage truck of carriage. BACKGROUND
[0002] At present in the environmental sanitation market, detachable garbage truck of carriage is widely used, but the existing detachable garbage truck of carriage usually only has the function of being unable to open the hook lock when lifting the box body, and there is no detection for whether the L arm telescoping and the large arm lifting on the garbage truck are in place, and there is no interlocking of the action, so when being touched artificially, the L arm telescoping and the large arm lifting of the garbage truck are easy to be confused and accidents occur, and when the hooking or unloading operation is carried out after the L arm or the large arm does not reach the specified position, the center of gravity of the whole vehicle may change and side or back overturning occurs, safety accidents happen and safety hazards are produced. SUMMARY
[0003] The utility model discloses to overcome the problem that there is no detection for whether the L arm telescoping and the large arm lifting on the garbage truck are in place, and there is no interlocking of the action, so safety accidents are easy to happen, and when the hooking or unloading operation is carried out after the L arm or the large arm does not reach the specified position, the center of gravity of the whole vehicle may change and side or back overturning occurs, safety accidents happen and safety hazards are produced, and provide a control circuit of detachable garbage truck of carriage.
[0004] In order to achieve the above-mentioned purpose, the utility model provides the following technical scheme: a control circuit of detachable garbage truck of carriage, including execution circuit, power supply circuit and be used for controlling the on-off of execution circuit control circuit, execution circuit and control circuit are parallelly connected in the power supply circuit respectively, execution circuit includes large arm lifting branch, L arm telescoping branch, control circuit includes first control branch, third control branch, second control branch and fourth control branch first control branch is used for controlling the on-off of L arm telescoping branch, first control branch is interlocked with second control branch and fourth control branch, second control branch, third control branch and fourth control branch are used for controlling the on-off of large arm lifting branch together.
[0005] The control circuit of detachable garbage truck of carriage as described above, the first control branch includes normally closed proximity switch SQ2 and relay KA1, the input end of normally closed proximity switch SQ2 is connected to the anode of power supply circuit, the output end of normally closed proximity switch SQ2 is connected to the input end of the coil of relay KA1, the output end of the coil of relay KA1 is connected to the cathode of power supply circuit, the contact of relay KA1 is connected to L arm telescoping branch.
[0006] The control circuit of the detachable garbage truck as described above, the L-arm telescopic operation knob is connected to the positive pole of the power supply circuit at one end and to the L-arm telescopic branch at the other end, for switching on and off between the L-arm forward extension branch and the L-arm retraction branch, the L-arm forward extension branch comprises the normally open contact KA1-2 of the relay KA1 and the electromagnetic valve Y3, the output end of the normally open contact KA1-2 is connected to the input end of the electromagnetic valve Y3, and the output end of the electromagnetic valve Y3 is connected to the negative pole of the power supply circuit, and the L-arm retraction branch comprises the normally open contact KA1-3 of the relay KA1 and the electromagnetic valve Y4, the output end of the normally open contact KA1-3 is connected to the input end of the electromagnetic valve Y4, and the output end of the electromagnetic valve Y4 is connected to the negative pole of the power supply circuit.
[0007] The control circuit of the detachable garbage truck as described above, the second control branch comprises the normally open proximity switch SQ3 and the relay KA2, one end of the normally closed contact KA1-4 of the relay KA1 is connected to the positive pole of the power supply circuit, and the other end is connected to the input end of the normally open proximity switch SQ3, the output end of the normally open proximity switch SQ3 is connected to the coil input end of the relay KA2, and the coil output end of the relay KA2 is connected to the negative pole of the power supply circuit.
[0008] The control circuit of the detachable garbage truck as described above, the third control branch comprises the normally open proximity switch SQ5 and the relay KA5, the output end of the normally open proximity switch SQ5 is connected to the positive pole of the power supply circuit, the output end of the normally open proximity switch SQ5 is connected to the input of the coil of the relay KA5, and the output end of the coil of the relay KA5 is connected to the negative pole of the power supply circuit.
[0009] The control circuit of the detachable garbage truck as described above, the big arm lift operation knob is connected to the positive pole of the power supply circuit at one end and connected to the big arm lift branch at the other end, for switching on and off between the big arm lifting branch and the big arm descending branch, the big arm lifting branch includes the normally open contact KA2-1 of the relay KA2, the normally closed contact KA5-1 of the relay KA5 and the electromagnetic valve Y1, the output end of the normally open contact KA2-1 is connected to the input end of the normally closed contact KA5-1, the output end of the normally closed contact KA5-1 is connected to the electromagnetic valve Y1, the output end of the electromagnetic valve Y1 is connected to the negative pole of the power supply circuit, the big arm descending branch includes the normally closed contact KA5-2 of the relay KA5 and the electromagnetic valve Y2, one end of the normally closed contact KA5-2 is connected to the big arm lift operation knob, the other end of the normally closed contact KA5-2 is connected to the input end of the electromagnetic valve Y2, the output end of the electromagnetic valve Y2 is connected to the negative pole of the power supply circuit.
[0010] The control circuit of the detachable garbage truck as described above, the fourth control branch includes the normally open contact KA1-1 of the relay KA1, the proximity switch SQ4 and the relay KA4, one end of the normally open contact KA1-1 is connected to the positive pole of the power supply circuit, the other end is connected to the input end of the proximity switch SQ4, the output end of the proximity switch SQ4 is connected to the coil of the relay KA4, the coil output end of the relay KA4 is connected to the negative pole of the power supply circuit.
[0011] The control circuit of the detachable garbage truck as described above, the normally open contact KA4-1 of the relay KA4 is connected in parallel with the normally open contact KA2-1 and the normally closed contact KA5-1.
[0012] The interlocking control circuit of the detachable garbage truck as described above, including the fifth control branch, the fifth control branch includes the normally closed proximity switch SQ1, the relay KA3, the output end of the normally closed proximity switch SQ1 is connected to the positive pole of the power supply circuit, the output end of the normally closed proximity switch SQ1 is connected to the input end of the coil of the relay KA3, the output end of the coil of the relay KA3 is connected to the negative pole of the power supply circuit.
[0013] The control circuit of the detachable garbage truck as described above, including the electromagnetic valve Y7, one end of the normally open contact KA3-2 of the relay KA3 is connected to the positive pole of the power supply circuit, the other end is connected to one end of the normally closed contact KA5-3 of the relay KA5, the other end of the normally closed contact KA5-3 is connected to the input end of the electromagnetic valve Y7, the output end of the electromagnetic valve Y7 is connected to the output end of the coil of the relay KA3.
[0014] Compared with the prior art, the beneficial effects of the technical scheme are that: after the structure of the utility model is adopted, the first control branch is used for controlling the L-arm telescopic branch, the second control branch, the third control branch and the fourth control branch are used for controlling the on-off of the large-arm lifting branch together, the action state of the garbage truck is detected through the control circuit, the on-off control of the execution circuit is performed through the detected state, the interlocking of the garbage truck action is realized, the occurrence of accidents caused by human error operation is avoided, and the interlocking of the garbage truck action can make the garbage truck in action only when the box is in a suitable position to perform the next action, effectively avoiding the occurrence of safety accidents and safety hazards caused by the change of the whole vehicle gravity center and the side or rear overturning when the box performs the hooking and unhooking operation in an unsuitable place.
[0015] The additional aspects and advantages of the utility model will be partly given in the following description, partly will become obvious from the following description, or be understood through the practice of the utility model. BRIEF DESCRIPTION OF DRAWINGS
[0016] In order to more clearly illustrate the technical scheme in the embodiments of the utility model or the prior art, the following will briefly introduce the drawings needed to be used in the embodiment or the prior art description, obviously, the drawings in the following description are only some embodiments of the utility model, and for those skilled in the art, other drawings can also be obtained according to these drawings without paying the creative labor.
[0017] Fig. 1 It is the electrical schematic diagram of the utility model;
[0018] Fig. 2 It is the electrical schematic diagram of the control circuit of the utility model;
[0019] Fig. 3 It is the electrical schematic diagram of the execution circuit of the utility model; DETAILED DESCRIPTION
[0020] The technical scheme in the embodiments of the utility model will be clearly and completely described below in conjunction with the drawings in the embodiments of the utility model, obviously, the described embodiments are only some embodiments of the utility model, not all the embodiments.Based on the embodiments in the utility model, all other embodiments obtained by those skilled in the art without paying the creative labor belong to the protection scope of the utility model.
[0021] As Figs. 1 to 3The utility model provides an control circuit of one kind of compartment detachable garbage truck, wherein the existing compartment detachable garbage truck includes garbage truck body, box, big arm, L arm, hook, hook lock and supporting wheel, when the garbage truck needs to unload the garbage in the box, first need to carry out the locking of hook lock to the box, then big arm action lifts the box, after lifting in place, extend L arm, make the garbage in the box pour out, when needing to carry out the box loading and unloading on the garbage truck body, need L arm to be in the retraction end point in big arm, lock hook is in the open state, supporting wheel is not in the retraction position (supporting state), when three conditions satisfy simultaneously, allow the box loading and unloading action.
[0022] The control circuit of the compartment detachable garbage truck includes an execution circuit 1, a power circuit 3, and a control circuit 2 for controlling the on-off of the execution circuit, the execution circuit 1 and the control circuit 2 are connected in parallel to the power circuit 3, the execution circuit 1 includes a big arm lifting branch 11 and an L arm telescopic branch 12, the control circuit 2 includes a first control branch 21, a third control branch 23, a second control branch 22, and a fourth control branch 24, the first control branch 21 is used for controlling the on-off of the L arm telescopic branch 12, the first control branch 21 is interlocked with the second control branch 22 and the fourth control branch 24, and the second control branch 22, the third control branch, and the fourth control branch 24 are used for controlling the on-off of the big arm lifting branch 11 together. After the structure of the utility model is adopted, the L arm telescopic branch can be controlled through the first control branch, the second control branch, the third control branch, and the fourth control branch are used for controlling the on-off of the big arm lifting branch together, the action state of the garbage truck is detected through the control circuit, the on-off of the execution circuit is controlled through the detected state, the interlocking of the garbage truck action is realized, the occurrence of accidents caused by human error operation is avoided, and the interlocking of the garbage truck action can make the box be in a suitable position before the next action is performed when the garbage truck is in action, which effectively avoids the change of the center of gravity of the whole vehicle, the side or rear overturning, the occurrence of safety accidents, and the generation of safety hazards when the box is in an unsuitable place for unloading operation.
[0023] Further, in order to avoid the damage of the machine caused by the L-arm still being able to extend and retract when the hook is in the locked state, the first control branch 21 comprises a normally closed proximity switch SQ2 for detecting the working state of the hook and a relay KA1, the input end of the normally closed proximity switch SQ2 is connected to the positive pole of the power supply circuit 3, the output end of the normally closed proximity switch SQ2 is connected to the input end of the coil of the relay KA1, the output end of the coil of the relay KA1 is connected to the negative pole of the power supply circuit 3, and the contacts of the relay KA1 are connected to the L-arm extension and retraction branch 12. The L-arm extension and retraction branch 12 comprises an L-arm extension branch and an L-arm retraction branch, one end of the L-arm extension and retraction operation knob 15 is connected to the positive pole of the power supply circuit 3, the other end of the L-arm extension and retraction operation knob 15 is connected to the L-arm extension and retraction branch 12, and the L-arm extension and retraction operation knob 15 is used to switch the on-off between the L-arm extension branch and the L-arm retraction branch, the L-arm extension branch comprises the normally open contacts KA1-2 of the relay KA1 and the electromagnetic valve Y3, the output end of the normally open contacts KA1-2 is connected to the input end of the electromagnetic valve Y3, and the output end of the electromagnetic valve Y3 is connected to the negative pole of the power supply circuit 3, and the L-arm retraction branch comprises the normally open contacts KA1-3 of the relay KA1 and the electromagnetic valve Y4, the output end of the normally open contacts KA1-3 is connected to the input end of the electromagnetic valve Y4, and the output end of the electromagnetic valve Y4 is connected to the negative pole of the power supply circuit 3. Since the proximity switch for detecting the working state of the hook is the normally closed proximity switch SQ2, when the hook is in the open state, the normally closed proximity switch SQ2 is turned on, at this time, the coil of the relay KA1 is turned on, the normally open contacts KA1-2 and the normally open contacts KA1-3 are in the closed state, and when the extension and retraction of the L-arm need to be operated, the L-arm can be extended or retracted by only operating the L-arm extension and retraction operation knob. Conversely, when the hook is in the locked state, the normally closed proximity switch SQ2 is turned off, the relay KA1 is not powered, and then the normally open contacts KA1-2 and the normally open contacts KA1-3 are in the closed state, the L-arm extension and retraction branch 12 cannot be turned on, the L-arm does not move, and the damage of the machine caused by the L-arm still being able to extend and retract when the hook is in the locked state is avoided.
[0024] As a specific embodiment rather than limitation, in order to successfully unload, the second control branch 22 includes a normally open proximity switch SQ3 and a relay KA2 for detecting the L-arm forward state, the normally closed contact KA1-4 of the relay KA1 is connected to the positive pole of the power supply circuit 3 at one end, and connected to the input end of the normally open proximity switch SQ3 at the other end, the output end of the normally open proximity switch SQ3 is connected to the coil input end of the relay KA2, and the coil output end of the relay KA2 is connected to the negative pole of the power supply circuit 3. When unloading, the hook state needs to be in the open state, and the L-arm is at the forward end point, so as to unload. Since the contact of the relay KA1 in the second control branch 22 is the normally closed contact KA1-4, when the hook is in the locked state, the coil of the relay KA1 is not powered, the normally closed contact KA1-4 is connected, the L-arm is at the forward end point, the proximity switch SQ3 is closed, and the second control branch is connected.
[0025] Further, in order to jointly control the unloading action with the second control branch 22, the third control branch 23 includes a normally open proximity switch SQ5 and a relay KA5 for detecting the state of the supporting wheel, the output end of the normally open proximity switch SQ5 is connected to the positive pole of the power supply circuit 3, the output end of the normally open proximity switch SQ5 is connected to the input of the coil of the relay KA5, and the output end of the coil of the relay KA5 is connected to the negative pole of the power supply circuit 3. The proximity switch SQ5 can be used to detect the retracted position of the supporting wheel, when the supporting wheel is in the retracted position, the normally open proximity switch SQ5 is closed, and at this time the third control branch is connected.
[0026] As a specific embodiment, in order to prevent the locking hook from opening and the L-arm from being in the forward end position during unloading, the large-arm lifting operation knob 16 is connected to the positive pole of the power supply circuit 3 at one end and to the large-arm lifting branch 11 at the other end, for switching the large-arm lifting branch and the large-arm lowering branch. The large-arm lifting branch includes the normally open contact KA2-1 of the relay KA2, the normally closed contact KA5-1 of the relay KA5 and the electromagnetic valve Y1, the output end of the normally open contact KA2-1 is connected to the input end of the normally closed contact KA5-1, the output end of the normally closed contact KA5-1 is connected to the electromagnetic valve Y1, and the output end of the electromagnetic valve Y1 is connected to the negative pole of the power supply circuit 3. The large-arm lowering branch includes the normally closed contact KA5-2 of the relay KA5 and the electromagnetic valve Y2, one end of the normally closed contact KA5-2 is connected to the large-arm lifting operation knob 16, the other end of the normally closed contact KA5-2 is connected to the input end of the electromagnetic valve Y2, and the output end of the electromagnetic valve Y2 is connected to the negative pole of the power supply circuit 3. When the locking hook is in the locked state, the normally closed proximity switch SQ2 is disconnected, the coil of the relay KA1 is not powered, and the normally closed contact KA1-4 is in the closed state. When the L-arm is in the forward end position, the second control circuit 22 is connected, the normally open contact KA2-1 on the large-arm lifting branch 111 is connected, and the normally open proximity switch SQ5 is not connected when the carrier wheel is not retracted to the position. The coil of the relay KA5 is not powered, and the normally closed contact KA5-1 is in the connected state. By operating the large-arm lifting operation knob 16, the electromagnetic valve Y1 and the electromagnetic valve Y2 are connected, and the L-arm can be lifted. Conversely, when the L-arm is not in the forward end position and the locking hook is not locked, the electromagnetic valve Y1 and the electromagnetic valve Y2 cannot be powered, and the L-arm cannot be lifted.
[0027] As a specific embodiment, but not limited, in order to achieve the garbage truck loading and unloading box, the fourth control branch 24 includes the normally open contact KA1-1 of the relay KA1, the proximity switch SQ4 for detecting the L arm retracted state, and the relay KA4, one end of the normally open contact KA1-1 is connected to the positive of the power supply circuit 3, the other end is connected to the input of the proximity switch SQ4, the output of the proximity switch SQ4 is connected to the coil of the relay KA4, the coil output of the relay KA4 is connected to the negative of the power supply circuit 3. The normally open contact KA4-1 of the relay KA4 is connected in parallel with the normally open contact KA2-1 and the normally closed contact KA5-1. When the hook lock is in the open state, the normally closed proximity switch SQ2 is turned on, so that the coil of the relay KA1 is powered on, the normally open contact KA1-1 in the fourth control branch 24 is closed, and when the L arm is retracted to the retracted position, the normally open proximity switch SQ4 is turned on, at this time the coil of the relay KA4 is powered on, so that the normally open contact KA4-1 on the large arm lifting branch is turned on. When the large arm lifting branch is selected by the large arm lifting operation knob 16, the large arm lifting branch is turned on, the electromagnetic valve Y1 is actuated, and the L arm is lifted.
[0028] Further, in order to make the supporting wheel automatically retract, the fifth control branch 25 is included, the fifth control branch 25 includes the normally closed proximity switch SQ1 for detecting the L arm horizontal state, the relay KA3, the output of the normally closed proximity switch SQ1 is connected to the positive of the power supply circuit 3, the output of the normally closed proximity switch SQ1 is connected to the input of the coil of the relay KA3, the output of the coil of the relay KA3 is connected to the negative of the power supply circuit. The electromagnetic valve Y7 is included, one end of the normally open contact KA3-2 of the relay KA3 is connected to the positive of the power supply circuit 3, the other end is connected to one end of the normally closed contact KA5-3 of the relay KA5, the other end of the normally closed contact KA5-3 is connected to the input of the electromagnetic valve Y7, the output of the electromagnetic valve Y7 is connected to the output of the coil of the relay KA3. When the L arm is in the horizontal state, the normally closed proximity switch SQ1 is disconnected, the supporting wheel is not in the retracted position, at this time the normally closed contact KA5-3 is turned on, the normally closed contact KA3-2 is turned on, so that the electromagnetic valve Y7 is contacted, and the supporting wheel is automatically retracted.
[0029] Further, a hook lock operation knob 17 is included, the hook lock operation knob 17 is connected with a hook lock control branch 13, the hook lock control branch 13 includes an electromagnetic valve Y5 for hook lock locking and an electromagnetic valve Y6 for hook lock opening, the electromagnetic valve Y5 and the electromagnetic valve Y6 are commonly connected to the hook lock operation knob 17 at one end and connected to the power supply circuit 3 at the other end, and a carrier wheel operation knob 18 is further included, the carrier wheel operation knob 18 is connected with a carrier wheel control branch 14, the carrier wheel control branch 14 includes an electromagnetic valve Y7 for controlling carrier wheel retraction and an electromagnetic valve Y8 for controlling carrier wheel extension, and the electromagnetic valve Y7 and the electromagnetic valve Y8 are commonly connected to the carrier wheel operation knob 18.
[0030] The specific working principle of the embodiment is as follows: through circuit control, when the hook lock is in an open state, a normally closed proximity switch SQ2 is turned on, the coil of a relay KA1 is turned on and off, normally open contacts KA1-2 and KA1-3 on an L arm retraction branch are turned on, the L arm can be retracted, and vice versa, when unloading is needed, the hook lock is in a locked state, the carrier wheel is in a supporting state, and the L arm is at a front extension end point, at this time, a normally open contact KA2-1 in a large arm lifting branch 111 is closed, a normally closed contact KA5- is in a closed state, and through operation of a large arm lifting operation knob 16, the large arm lifting branch is selected and turned on, and the L arm can be lifted, when a box or equipment needs to be unloaded or loaded, the hook lock is in an open state, the L arm is at an inner retraction end point, and the coil of a relay KA4 is energized, at this time, a normally open contact KA4-1 on the large arm lifting branch is closed, the large arm lifting branch is turned on, when the L arm is at a horizontal position, a normally closed proximity switch SQ1 is turned off, the coil of a relay KA3 is not energized, a normally closed contact KA3-2 is turned on, the carrier wheel is not in a retracted position, and the electromagnetic valve Y7 is energized, and the carrier wheel is automatically retracted to the position.
[0031] It is obvious for those skilled in the art that the present application is not limited to the details of the above-mentioned exemplary embodiments, and the present application can be implemented in other specific forms without departing from the spirit or essential characteristics of the present application. Therefore, the embodiments should be regarded as exemplary and non-limiting, and the scope of the present application is defined by the appended claims rather than the above description, and all changes falling within the meaning and scope of the equivalent elements of the claims are intended to be included in the present application. Any reference signs in the claims should not be regarded as limiting the claims.
Claims
1. A control circuit of a body detachable garbage truck, comprising an execution circuit (1), a power supply circuit (3) and a control circuit (2) for controlling the on-off of the execution circuit, characterized in that, The execution circuit (1) and control circuit (2) are respectively parallel to the power circuit (3), the execution circuit (1) includes large arm lifting branch (11), L arm telescopic branch (12), the control circuit (2) includes first control branch (21), third control branch (23), second control branch (22) and fourth control branch (24) the first control branch (21) is used for controlling the on-off of L arm telescopic branch (12), the first control branch (21) is interlocked with the second control branch (22) and fourth control branch (24), the second control branch (22), third control branch and fourth control branch (24) are used for controlling the on-off of the large arm lifting branch (11) in common.
2. The control circuit for a body dump refuse vehicle of claim 1 wherein, The first control branch (21) includes normally closed proximity switch SQ2 and relay KA1, the input end of the normally closed proximity switch SQ2 is connected to the positive pole of the power circuit (3), the output end of the normally closed proximity switch SQ2 is connected to the input end of the coil of the relay KA1, the output end of the coil of the relay KA1 is connected to the negative pole of the power circuit (3), the contact of the relay KA1 is connected to the L arm telescopic branch (12).
3. The control circuit for a body dump truck of claim 2 wherein, Including L arm telescopic operation knob (15), the L arm telescopic branch (12) includes L arm forward extension branch and L arm retraction branch, one end of the L arm telescopic operation knob (15) is connected to the positive pole of the power circuit (3), the other end is connected to the L arm telescopic branch (12), for switching on-off between L arm forward extension branch and L arm retraction branch, the L arm forward extension branch includes the normally open contact KA1-2 of the relay KA1 and electromagnetic valve Y3, the output end of the normally open contact KA1-2 is connected to the input end of the electromagnetic valve Y3, the output end of the electromagnetic valve Y3 is connected to the negative pole of the power circuit (3), the L arm retraction branch includes the normally open contact KA1-3 of the relay KA1 and electromagnetic valve Y4, the output end of the normally open contact KA1-3 is connected to the input end of the electromagnetic valve Y4, the output end of the electromagnetic valve Y4 is connected to the negative pole of the power circuit (3).
4. The control circuit for a body dump truck of claim 2 wherein, The second control branch (22) includes normally open proximity switch SQ3 and relay KA2, one end of the normally closed contact KA1-4 of the relay KA1 is connected to the positive pole of the power circuit (3), the other end is connected to the input end of the normally open proximity switch SQ3, the output end of the normally open proximity switch SQ3 is connected to the coil input end of the relay KA2, the coil output end of the relay KA2 is connected to the negative pole of the power circuit (3).
5. The control circuit for a body dump truck of claim 4 wherein, The third control branch (23) includes normally open proximity switch SQ5 and relay KA5, the output end of the normally open proximity switch SQ5 is connected to the positive pole of the power circuit (3), the output end of the normally open proximity switch SQ5 is connected to the input of the coil of the relay KA5, the output end of the coil of the relay KA5 is connected to the negative pole of the power circuit (3).
6. The control circuit for a body dump truck of claim 5 wherein, The big arm lift operation knob (16) is connected to the positive pole of the power supply circuit (3) at one end and connected to the big arm lift branch (11) at the other end, for switching on and off between the big arm lifting branch and the big arm descending branch, the big arm lifting branch includes the normally open contact KA2-1 of the relay KA2, the normally closed contact KA5-1 of the relay KA5 and the electromagnetic valve Y1, the output end of the normally open contact KA2-1 is connected to the input end of the normally closed contact KA5-1, the output end of the normally closed contact KA5-1 is connected to the electromagnetic valve Y1, the output end of the electromagnetic valve Y1 is connected to the negative pole of the power supply circuit (3), the big arm descending branch includes the normally closed contact KA5-2 of the relay KA5 and the electromagnetic valve Y2, one end of the normally closed contact KA5-2 is connected to the big arm lift operation knob (16), the other end of the normally closed contact KA5-2 is connected to the input end of the electromagnetic valve Y2, the output end of the electromagnetic valve Y2 is connected to the negative pole of the power supply circuit (3).
7. The control circuit for a body dump truck of claim 6 wherein, The fourth control branch (24) includes the normally open contact KA1-1 of the relay KA1, the proximity switch SQ4 and the relay KA4, one end of the normally open contact KA1-1 is connected to the positive pole of the power supply circuit (3), the other end is connected to the input end of the proximity switch SQ4, the output end of the proximity switch SQ4 is connected to the coil of the relay KA4, the coil output end of the relay KA4 is connected to the negative pole of the power supply circuit (3).
8. The control circuit for a body dump truck of claim 7 wherein, The normally open contact KA4-1 of the relay KA4 is connected in parallel with the normally open contact KA2-1 and the normally closed contact KA5-1.
9. The control circuit for a body dump truck of claim 6 wherein, The fifth control branch (25) includes the normally closed proximity switch SQ1 and the relay KA3, the output end of the normally closed proximity switch SQ1 is connected to the positive pole of the power supply circuit (3), the output end of the normally closed proximity switch SQ1 is connected to the input end of the coil of the relay KA3, the output end of the coil of the relay KA3 is connected to the negative pole of the power supply circuit.
10. The control circuit for a body dump truck of claim 9 wherein, The electromagnetic valve Y7, one end of the normally open contact KA3-2 of the relay KA3 is connected to the positive pole of the power supply circuit (3), the other end is connected to one end of the normally closed contact KA5-3 of the relay KA5, the other end of the normally closed contact KA5-3 is connected to the input end of the electromagnetic valve Y7, the output end of the electromagnetic valve Y7 is connected to the output end of the coil of the relay KA3.