Lorry-mounted crane electric control direction judgment mechanism based on travel switch

Abstract

The utility model discloses a lorry-mounted crane electric control direction judgment mechanism based on a travel switch, and belongs to the technical field of lorry-mounted cranes. The multi-way valve is characterized in that the multi-way valve comprises a handle, a multi-way valve body, a controller, a travel switch and a trigger block, the handle is connected with the end, corresponding to a valve element, of the multi-way valve body, the other end of the valve element penetrates out of a rear end cover of the multi-way valve body, and the trigger block is connected with the other end of the corresponding valve element; the travel switch is installed on a rear end cover of the multi-way valve through a supporting plate, the trigger end of the travel switch right faces the trigger block, and the signal end of the travel switch is in communication connection with the signal end of the controller. The handle moves, the trigger block is pulled through the valve element, and therefore the travel switch is triggered, and a signal is transmitted to the controller. According to the utility model, the problem that dangerous operation cannot be avoided when the crane is in a dangerous working condition is solved, and accidents such as rollover and arm folding caused by misoperation of an operator in a dangerous direction are avoided; and compared with hydraulic control direction judgment, the pipeline structure is simple, and the cost is greatly reduced.

Description

Technical Field

[0001] The utility model relates to an electric control direction judgment mechanism of a truck crane based on a travel switch, belonging to the technical field of truck cranes. Background Art

[0002] The bottom-operated straight-arm truck crane is equipped with two main and auxiliary controls. The main and auxiliary controls are respectively equipped with four handles to control the four actions of boom lowering, boom extension and retraction, winch recovery, and crane rotation. The four handles of the main control are respectively connected to the valve core of the multi-way valve, and the other ends of the four valve cores are connected to the four handles of the auxiliary control through horizontal tie rods to achieve linkage.

[0003] During the operation of a straight-arm truck crane, overload conditions are inevitable. Under overload conditions, the overturning moment exerted on the crane is in a critical state. At this time, if the crane continues to operate in the dangerous direction (i.e. the direction of increasing torque), it will cause damage to the crane and even cause serious consequences such as casualties to nearby personnel.

[0004] At present, most domestic straight-arm truck cranes adopt the following two methods to prevent overloading:

[0005] First, under overload conditions, the three-color light or buzzer alarm can serve as a warning, but it is inevitable that there will be some risks due to human error.

[0006] Second, hydraulic control direction judgment. Under overload conditions, a multi-unit unloading valve is used to control each unit of the crane separately, that is, each movement of the crane is equipped with an unloading valve, and each dangerous direction of movement is unloaded separately. The sensor then transmits the signal to the controller, and the controller issues a command to the main unloading valve to put the crane into an emergency stop state. Some of the problems it has include: high cost, inconvenient installation and maintenance, and complex pipeline directions. Utility Model Content

[0007] The purpose of the utility model is to address the deficiencies of the above-mentioned prior art and provide an electric control direction judgment mechanism for a truck crane based on a travel switch, which is suitable for a bottom-operated straight-arm truck crane. The travel switch is used as a signal receiver, and the dangerous direction of the crane is judged by electronic control. In combination with an overload signal, the direction judgment of the action limit is completed, and the total unloading valve of the crane is triggered to enter an emergency stop state, thereby ensuring safe operation.

[0008] The technical solution of the utility model is as follows:

[0009] An electrically controlled direction determination mechanism for a truck-mounted crane based on a travel switch is characterized in that it includes: a handle, a multi-way valve, a controller, a travel switch, and a trigger block. The handle is connected to the end of the corresponding valve core on the multi-way valve, the other end of the valve core extends through the rear end cover of the multi-way valve, and the trigger block is connected to the other end of the corresponding valve core; the travel switch is mounted on the rear end cover of the multi-way valve via a support plate, with the trigger end of the travel switch facing the trigger block, and the signal end of the travel switch is communicatively connected to the signal end of the controller; when the handle is displaced, the trigger block is pulled through the valve core, thereby triggering the travel switch and transmitting the signal to the controller.

[0010] In this solution, if the handle is still moved in the dangerous direction during an overload condition, the valve core will pull the trigger block, triggering the travel switch and sending a signal to the controller. The controller will only trigger the main unloading valve to de-energize after receiving the travel switch signal and the overload signal. Both signals are required and there is no order of priority. De-energizing the main unloading valve completes the truck crane's unloading function, ensuring safe operation.

[0011] Furthermore, the travel switches and trigger blocks are arranged in pairs, with three sets in total, which work with the three handles that control the luffing and lowering, boom extension and retraction, and winch retraction. Under overload conditions, if the luffing and lowering, boom extension and retraction, or winch retraction continue to operate, it will be dangerous. These three operating directions are dangerous directions.

[0012] Furthermore, the rear end cap is provided with a through hole for the valve core to pass through. The rear end cap is formed by connecting a gland and a connecting column. The gland has fixing holes at each corner. Four fixing bolts are inserted through the gland fixing holes to install the rear end cap on the rear end of the multi-way valve. The rear end of the multi-way valve is provided with four rear end caps, one for each of the four valve cores.

[0013] Furthermore, the tail of the support plate is bent into an L shape, and one side plate of the support plate is provided with two mounting holes; one side plate of the support plate is overlapped with the pressure cover part of the rear end cover, so that the two mounting holes of the support plate coincide with the two fixing holes of the pressure cover of the rear end cover respectively, and the two fixing bolts on the pressure cover are used to lock them, and the support plate and the rear end cover are fixedly connected, providing conditions for the installation of the travel switch, and no additional mounting holes need to be processed on the multi-way valve.

[0014] Furthermore, one side plate of the support plate is provided with an arc edge matching the rear end cover connecting column to avoid the cylindrical surface of the rear end cover connecting column, thereby facilitating installation.

[0015] Furthermore, the travel switch is a direct-acting travel switch with a steel roller. The travel switch push rod has an external thread. The other side plate of the support plate has a circular hole, through which the travel switch push rod passes. The push rod is connected to two locking nuts, one on each side of the support plate, to lock the travel switch to the support plate. The steel roller serves as the trigger end of the travel switch and contacts the trigger block.

[0016] Furthermore, the trigger block is formed by connecting a large-diameter cylinder and a small-diameter cylinder; the end face of the large-diameter cylinder is provided with a threaded hole, and the other end of the valve core is provided with an external thread, and the trigger block and the valve core are connected through the threaded hole and the external thread; the intersection of the small-diameter cylinder and the large-diameter cylinder is an arc surface that matches the steel roller of the travel switch, forming a boss that triggers the travel switch.

[0017] Furthermore, a pair of extension plates are provided at the small-diameter cylindrical end of the trigger block. The pair of extension plates are arranged opposite to each other and are respectively provided with through holes to form a fork-like structure for installing a tie rod connecting the main and auxiliary controls.

[0018] The multi-way valve in this utility model serves as the connecting body, with a support plate mounted on the rear end cover of the multi-way valve, and a travel switch fixed to the support plate. The multi-way valve spool extends from the rear end cover and is provided with external threads. The trigger block is internally threaded and connected to the spool. The trigger block is also machined with a fork-like structure and has through-holes on the side for mounting the tie rods connecting the primary and secondary controls. This utility model solves the problem of unavoidable dangerous operations when a crane encounters dangerous conditions, preventing accidents such as rollovers and arm breakage caused by operator misoperation in dangerous directions. Compared to hydraulically controlled direction determination, the pipeline structure is simpler, significantly reducing costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 It is a structural diagram of the utility model;

[0020] Figure 2 for Figure 1 Exploded view of

[0021] Figure 3 This is a schematic diagram of the installation of the rear end cover, trigger block, travel switch, and support plate in the utility model;

[0022] Figure 4 for Figure 3 A top view of

[0023] Figure 5 This is a schematic diagram of the installation of the rear end cover and the support plate in the utility model;

[0024] Figure 6 This is a schematic diagram of the support plate in the present invention;

[0025] Figure 7 Schematic diagram of the trigger block in the present invention (L1 is the outer diameter of the large-diameter cylinder of the trigger block, and L2 is the outer diameter of the small-diameter cylinder of the trigger block);

[0026] Figure 8 for Figure 7 A partial cross-sectional view of

[0027] Figure 9 Schematic diagram of the travel switch in the present utility model (h is the total stroke of the travel switch steel roller);

[0028] Figure 10 This is a diagram showing the displacement and flow matching of the multi-way valve core in the embodiment;

[0029] Figure 11 A diagram showing the relationship between the handle, valve core, travel switch, and trigger block in the embodiment (the travel switch is not triggered);

[0030] Figure 12 A diagram showing the relationship between the handle, valve core, travel switch, and trigger block in the embodiment (triggering the travel switch);

[0031] In the figure: handle 1, multi-way valve 2, travel switch 3, trigger block 4, large-diameter cylinder 4-1, threaded hole 4-1-1, small-diameter cylinder 4-2, extension plate 4-2-1, through hole 4-2-2, boss 4-3, valve core 5, external thread 5-1, rear end cover 6, pressure cover 6-1, connecting column 6-2, fixing bolt 7, support plate 8, mounting hole 8-1, arc edge 8-2, circular hole 8-3, lock nut 9, tie rod 10. DETAILED DESCRIPTION

[0032] An electric control direction judgment mechanism for a truck-mounted crane based on a travel switch, such as Figure 1 、 2 As shown, the system comprises a handle 1, a multi-way valve 2, a controller, a travel switch 3, and a trigger block 4. There are four handles, one for controlling luffing, boom extension, winch retraction, and crane slewing. Four valve cores 5 and four rear end caps 6 are provided. The travel switches and trigger blocks are arranged in pairs, with three sets in total, corresponding to the three handles controlling luffing, boom extension, and winch retraction (three dangerous directions).

[0033] like Figure 3 、 Figure 4 、 Figure 5 As shown, the rear end cover 6 is provided with a through hole for the valve core 5 to pass through, and the rear end cover is connected by a pressure cover 6-1 and a connecting column 6-2; the four corners of the pressure cover are respectively provided with fixing holes, and four fixing bolts 7 are passed through the fixing holes of the pressure cover to install the rear end cover at the rear end of the multi-way valve.

[0034] like Figure 6 As shown, the rear end of the support plate 8 is bent into an L-shape, and one side of the support plate is provided with two mounting holes 8-1. This side of the support plate is partially overlapped with the gland of the rear end cover, so that the two mounting holes of the support plate coincide with the two fixing holes of the gland. The two fixing bolts 7 on the gland are used to tighten the support plate and secure the rear end cover. One side of the support plate is provided with a circular edge 8-2 that matches the connecting column of the rear end cover, avoiding the cylindrical surface of the connecting column of the rear end cover.

[0035] like Figure 7 、 Figure 8 As shown, the trigger block 4 is composed of a large-diameter cylinder 4-1 and a small-diameter cylinder 4-2 connected together. The large-diameter cylinder has a threaded hole 4-1-1 on its end, and the other end of the valve core has an external thread 5-1. The trigger block and valve core are connected via the threaded hole and external thread. The intersection of the small-diameter and large-diameter cylinders forms a circular arc, forming a boss 4-3 that triggers the travel switch. A pair of extension plates 4-2-1 are installed at the ends of the small-diameter cylinder of the trigger block. These extension plates are arranged opposite each other and each has a through-hole 4-2-2 for mounting the tie rods connecting the primary and secondary controls.

[0036] like Figure 9 As shown, travel switch 3 is a direct-acting travel switch with a steel roller. The travel switch's push rod is externally threaded and secured with two locknuts 9. The other side of the support plate has a circular hole 8-3 through which the travel switch's push rod passes. Two locknuts 9, one on each side of the support plate, secure the travel switch to the support plate. The steel roller of the travel switch mates with the arcuate surface of the trigger block, allowing for slight compression of the travel switch. The central axis of the travel switch and the central axis of the trigger block are perpendicular and should remain in the same horizontal plane.

[0037] like Figure 11 、 Figure 12 As shown in the figure, the internal structure of the truck-mounted crane's multi-way valve converts the handle's fixed-point rotation into horizontal movement of the valve core (this is the principle of the multi-way valve mechanism and is not described in detail here). When the handle is pushed to the right, the trigger block, threadedly connected to the multi-way valve core, moves leftward along with the valve core. At this time, the travel switch does not roll onto the trigger block's boss and is therefore not triggered. When the handle is pushed to the left, the trigger block moves to the right, at which point the travel switch rolls onto the trigger block's boss, triggering it.

[0038] The controller will trigger the total unloading valve to lose power only after receiving the travel switch signal and the overload signal. Both signals are indispensable and there is no order of priority. The total unloading valve loses power to complete the unloading function of the truck crane to ensure safe operation.

[0039] In one embodiment of the present invention, according to Figure 10 In the multi-way valve spool displacement-flow matching diagram, there is a spool displacement area (dead zone) where the flow is 0 in the multi-way valve. The flow is always 0 without change within 1mm of spool displacement. It is required that the spool displacement does not exceed the upper limit of the dead zone (the trigger displacement is tentatively set to 80% of the upper limit of the dead zone) before the travel switch is triggered to recognize the displacement signal and output. To ensure that the travel switch is triggered, the radius difference between the large-diameter cylinder and the small-diameter cylinder on the trigger block should be less than or equal to the total stroke of the travel switch, that is, .

Claims

1. An electric control direction judgment mechanism for a truck-mounted crane based on a travel switch, characterized in that: include: A handle, a multi-way valve, a controller, a travel switch, and a trigger block. The handle is connected to the end of the corresponding valve core on the multi-way valve, the other end of the valve core passes through the rear end cover of the multi-way valve, and the trigger block is connected to the other end of the corresponding valve core; The travel switch is installed on the rear end cover of the multi-way valve through a support plate, and the trigger end of the travel switch is opposite to the trigger block, and the signal end of the travel switch is communicatively connected with the signal end of the controller; when the handle is displaced, the trigger block is pulled through the valve core, thereby triggering the travel switch and transmitting the signal to the controller.

2. The electric control direction judgment mechanism of a truck-mounted crane based on a travel switch according to claim 1 is characterized in that: The travel switch and the trigger block are arranged in pairs, with three groups in total, which respectively cooperate with the three handles for controlling the luffing and falling, the extension and retraction of the boom, and the winch recovery.

3. The electric control direction judgment mechanism of a truck-mounted crane based on a travel switch according to claim 1 is characterized in that: The rear end cover is provided with a through hole for the valve core to pass through, and the rear end cover is connected by a pressure cover and a connecting column; the four corners of the pressure cover are respectively provided with fixing holes, and four fixing bolts are passed through the fixing holes of the pressure cover to install the rear end cover at the rear end of the multi-way valve.

4. The electric control direction determination mechanism of a truck-mounted crane based on a travel switch according to claim 3 is characterized in that: The tail of the support plate is bent into an L shape, and one side plate of the support plate is provided with two mounting holes, which respectively coincide with the two fixing holes of the rear end cover pressure cover and are locked with a common fixing bolt to fix the support plate to the rear end cover, and one side plate of the support plate is provided with an arc edge that matches the rear end cover connecting column.

5. The electric control direction determination mechanism of a truck-mounted crane based on a travel switch according to claim 4 is characterized in that: The travel switch is a direct-acting travel switch with a steel roller, and the push rod of the travel switch is provided with an external thread; the other side plate of the support plate is provided with a circular hole for the travel switch push rod to pass through, and two locking nuts are connected to the push rod, and the two locking nuts are respectively located on both sides of the support plate to lock the travel switch and the support plate.

6. The electric control direction determination mechanism of a truck-mounted crane based on a travel switch according to claim 5 is characterized in that: The trigger block is formed by connecting a large-diameter cylinder and a small-diameter cylinder; the end face of the large-diameter cylinder is provided with a threaded hole, and the other end of the valve core is provided with an external thread. The trigger block and the valve core are connected through the threaded hole and the external thread; the intersection of the small-diameter cylinder and the large-diameter cylinder is an arc surface that matches the steel roller of the travel switch.

7. The electric control direction determination mechanism of a truck-mounted crane based on a travel switch according to claim 6 is characterized in that: A pair of extension plates are provided at the small diameter cylindrical end of the trigger block. The pair of extension plates are arranged opposite to each other and are respectively provided with through holes for installing the tie rods connecting the main and auxiliary controls.

Images