Safety protection device for lorry-mounted crane

Abstract

The invention discloses a lorry-mounted crane safety protection device which comprises a limiting pin detection switch, a buzzer, an instrument relay and an alarm relay. One end of the limiting pin detection switch, one end of a normally-closed contact of the instrument relay and one end of a normally-open contact of the alarm relay are connected with the positive electrode of a lorry-mounted crane power supply, and one end of a coil of the instrument relay and one end of a coil of the alarm relay are connected with the other end of the limiting pin detection switch; the other end of the instrument relay coil and the other end of the alarm relay coil are both grounded, the other end of the normally closed contact of the instrument relay is connected with an instrument in a cab, and the buzzer is connected with the other end of the normally open contact of the alarm relay. When the limiting pin is inserted into the rotary table, the buzzer is used for alarming and reminding, and when the limiting pin is not inserted, the instrument is used for reminding that the limiting pin is not inserted, so that safety accidents caused when the lorry-mounted crane is in a running state are avoided.

Description

Technical Field

[0001] The invention relates to the technical field of truck-mounted cranes, in particular to a safety protection device for truck-mounted cranes. Background Art

[0002] A truck mounted crane, also known as a lorry crane, is a device that can lift, rotate and hoist cargo. It is usually mounted on a truck and is mainly composed of a truck chassis, a turntable and a boom.

[0003] At present, when a truck-mounted crane is in operation, if the limit pin used for locking the turntable is not pulled out, directly rotating the turntable will cause the turntable to shear, and the limit pin, turntable and turntable support to tear, thereby damaging the truck-mounted crane. When the boom of the truck-mounted crane is located directly in front of the cab and is in a driving condition, if the limit pin is not inserted on the turntable, the truck-mounted crane will brake or turn, causing the turntable to rotate, and the boom or hook of the truck-mounted crane will hit the vehicles, objects and people near the truck-mounted crane, causing property damage or casualties. Summary of the invention

[0004] The technical problem to be solved by the present invention is to provide a safety protection device for a truck crane. When a limit pin is inserted into a turntable, an alarm is issued to avoid accidental rotation of the turntable. When the limit pin is not inserted into the turntable, a non-insertion reminder is issued through an instrument to avoid a safety accident when the truck crane is in a driving state when the limit pin is not inserted.

[0005] The technical solution of the present invention is:

[0006] A safety protection device for a truck-mounted crane comprises a limit pin detection switch, a buzzer, an instrument relay and an alarm relay, wherein the buzzer is arranged on the truck-mounted crane, the limit pin detection switch is fixedly arranged just below a turntable support and faces a support limit pin hole on the turntable support, a turntable is rotatably connected to the turntable support, and a front turntable limit pin hole and a rear turntable limit pin hole symmetrical along the radial direction of the turntable are arranged on the turntable, when a boom connected to the turntable is located just in front of a cab, the front turntable limit pin hole and the support limit pin hole overlap up and down, and the limit pin is inserted into the front turntable limit pin hole and the support limit pin hole, and when the boom is located just behind the cab, the rear turntable limit pin hole and the support limit pin hole overlap up and down, and the limit pin is inserted into the rear turntable limit pin hole and the support limit pin hole;

[0007] One end of the limit pin detection switch, one end of the normally closed contact of the instrument relay and one end of the normally open contact of the alarm relay are all connected to the positive pole of the power supply of the truck crane, one end of the instrument relay coil and one end of the alarm relay coil are both connected to the other end of the limit pin detection switch, the other end of the instrument relay coil and the other end of the alarm relay coil are both grounded, the other end of the normally closed contact of the instrument relay is connected to the instrument in the cab, one end of the buzzer is connected to the other end of the normally open contact of the alarm relay, and the other end of the buzzer is grounded.

[0008] It also includes a unloading solenoid valve, which is connected to the hydraulic actuator of the truck crane for unloading the hydraulic actuator, one end of the unloading solenoid valve is connected to the other end of the normally open contact of the alarm relay, and the other end of the unloading solenoid valve is grounded.

[0009] The buzzer is arranged on the turntable support.

[0010] A turntable seat is arranged on the turntable, one end of the limit pin pull rope is connected to the turntable seat, and the other end of the limit pin pull rope is connected to the limit pin.

[0011] The buzzer is provided with a manual switch, one end of the manual switch is connected to the other end of the normally open contact of the alarm relay, the other end of the manual switch is connected to one end of the buzzer, and the other end of the buzzer is grounded.

[0012] The limit pin detection switch is a photoelectric proximity switch.

[0013] Advantages of the present invention:

[0014] (1) The present invention is provided with a limit pin detection switch, which is linked with a buzzer and an instrument in the cab through an instrument relay and an alarm relay. When the limit pin detection switch detects that a limit pin is inserted into the turntable, an alarm is issued to prevent the staff from accidentally rotating the turntable and causing damage to the turntable. When the limit pin detection switch does not detect that a limit pin is inserted into the turntable, the instrument in the cab receives a signal and displays a prompt of "Please insert the turntable limit pin" to prevent the truck crane from starting to travel when the limit pin is not inserted, thereby preventing a safety accident.

[0015] (2) The present invention is provided with an unloading solenoid valve. When the limit pin detection switch detects that the limit pin is inserted into the turntable, the unloading solenoid valve receives a signal to unload the hydraulic actuator of the truck crane, thereby preventing the truck crane from performing any operation and preventing the turntable and the turntable support from shearing the limit pin.

[0016] (3) The present invention connects a limit pin pull rope to the turntable seat. When the limit pin detection switch detects that the limit pin is inserted into the turntable, in order to realize the rapid operation of the turntable, the operator sitting on the turntable seat can quickly pull the limit pin out of the turntable through the limit pin pull rope, thereby saving the operator's time for getting on and off the vehicle and improving work efficiency.

[0017] (4) The buzzer of the present invention can be turned off manually to avoid the continuous alarm of the buzzer during the driving of the truck crane with the limit pin inserted. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 It is a schematic diagram of the structure of the present invention arranged on a truck-mounted crane.

[0019] Figure 2 yes Figure 1 Enlarged view of part A in .

[0020] Figure 3 It is a schematic diagram of the partial structure where the boom is located directly in front of the cab.

[0021] Figure 4 It is a circuit diagram of the present invention.

[0022] Figure markings: 1-limit pin detection switch, 2-buzzer, 3-unloading solenoid valve, 4-instrument relay, 5-alarm relay, 6-manual switch, 7-power supply, 8-turntable support, 81-support limit pin hole, 9-turntable, 91-front turntable limit pin hole, 92-rear turntable limit pin hole, 10-limit pin, 11-boom, 12-instrument, 13-turntable seat, 14-limit pin pull rope. DETAILED DESCRIPTION

[0023] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0024] See Figure 1-Figure 4A safety protection device for a truck-mounted crane comprises a limit pin detection switch 1, a buzzer 2, a load-discharging solenoid valve 3, an instrument relay 4 and an alarm relay 5. The buzzer 2 is arranged on a turntable support 8. The limit pin detection switch 1 is a photoelectric proximity switch. The limit pin detection switch 1 is fixedly arranged directly below the turntable support 8 and faces a support limit pin hole 81 on the turntable support 8. A turntable 9 is rotatably connected to the turntable support 8. The load-discharging solenoid valve 3 is arranged on the turntable 9. The load-discharging solenoid valve 3 is connected to a hydraulic actuator of the truck-mounted crane and is used to control the hydraulic actuator. To perform unloading operation, the turntable 9 is provided with a front turntable limit pin hole 91 and a rear turntable limit pin hole 92 which are symmetrical along the radial direction of the turntable 9. When the boom 11 connected to the turntable 9 is located directly in front of the cab, the front turntable limit pin hole 91 and the support limit pin hole 81 overlap up and down, and the limit pin 10 is inserted into the front turntable limit pin hole 91 and the support limit pin hole 81. When the boom 11 is located directly behind the cab, the rear turntable limit pin hole 92 and the support limit pin hole 81 overlap up and down, and the limit pin 10 is inserted into the rear turntable limit pin hole 92 and the support limit pin hole 81.

[0025] One end of the limit pin detection switch 1, one end of the normally closed contact of the instrument relay 4 and one end of the normally open contact of the alarm relay 5 are all connected to the positive pole of the power supply 7 of the truck crane, one end of the coil of the instrument relay 4 and one end of the coil of the alarm relay 5 are all connected to the other end of the limit pin detection switch 1, the other end of the coil of the instrument relay 4 and the other end of the coil of the alarm relay 5 are both grounded, the other end of the normally closed contact of the instrument relay 4 is connected to the instrument 12 in the cab, the buzzer 2 is provided with a manual switch 6, one end of the manual switch 6 and one end of the unloading solenoid valve 3 are all connected to the other end of the normally open contact of the alarm relay 5, the other end of the manual switch 6 is connected to one end of the buzzer 2, and the other end of the buzzer 2 and the other end of the unloading solenoid valve 3 are both grounded;

[0026] A turntable seat 13 is provided on the turntable 9, one end of the limit pin pull rope 14 is connected to the turntable seat 13, and the other end of the limit pin pull rope 14 is connected to the limit pin 10. The length of the limit pin pull rope 14 is sufficient to ensure that when the limit pin 10 is inserted into the turntable 9, the limit pin pull rope 14 is in an unstressed state.

[0027] Working principle of the present invention:

[0028] When the operator is ready to operate the truck crane, the limit pin detection switch 1 detects that the limit pin 10 is inserted into the turntable 9, the limit pin detection switch 1 is closed, and the normally closed contact of the instrument relay 4 is disconnected. At this time, the instrument 12 cannot receive the signal, and the normally open contact of the alarm relay 5 is closed. At this time, the buzzer 2 is energized to alarm, prompting the operator that the limit pin has not been pulled out. At the same time, the unloading solenoid valve 3 receives a signal, and the unloading solenoid valve 3 performs an unloading operation on the hydraulic actuator to prevent the truck crane from making any operation and prevent the turntable 9 and the turntable support 8 from shearing the limit pin 10; when the operator is already on the turntable seat 13 on the turntable 9 and forgets to pull out the limit pin 10, the limit pin pull rope 14 can be pulled out of the turntable 9 by pulling the limit pin, saving the operator's time for getting on and off the vehicle and improving work efficiency.

[0029] When the truck-mounted crane is ready to start driving, and the limit pin detection switch 1 does not detect the insertion of the limit pin 10 on the turntable 9, the instrument 12 in the cab receives a signal and displays a prompt of "Please insert the turntable limit pin" to avoid the situation where the truck-mounted crane brakes or turns when the limit pin 10 is not inserted, causing the turntable to rotate, and the boom or hook of the truck-mounted crane hits the vehicles, objects, and personnel near the truck-mounted crane, causing property damage or casualties.

[0030] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A safety protection device for a truck-mounted crane, characterized in that: It includes a limit pin detection switch, a buzzer, an instrument relay and an alarm relay. The buzzer is arranged on the truck crane. The limit pin detection switch is fixedly arranged just below the turntable support and faces the support limit pin hole on the turntable support. The turntable support is rotatably connected with a turntable. The turntable is provided with a front turntable limit pin hole and a rear turntable limit pin hole which are symmetrical along the radial direction of the turntable. When the boom connected to the turntable is located just in front of the cab, the front turntable limit pin hole and the support limit pin hole overlap up and down, and the limit pin is inserted into the front turntable limit pin hole and the support limit pin hole. When the boom is located just behind the cab, the rear turntable limit pin hole and the support limit pin hole overlap up and down, and the limit pin is inserted into the rear turntable limit pin hole and the support limit pin hole. One end of the limit pin detection switch, one end of the normally closed contact of the instrument relay and one end of the normally open contact of the alarm relay are all connected to the positive pole of the power supply of the truck crane, one end of the instrument relay coil and one end of the alarm relay coil are both connected to the other end of the limit pin detection switch, the other end of the instrument relay coil and the other end of the alarm relay coil are both grounded, the other end of the normally closed contact of the instrument relay is connected to the instrument in the cab, one end of the buzzer is connected to the other end of the normally open contact of the alarm relay, and the other end of the buzzer is grounded.

2. A truck mounted crane safety protection device according to claim 1, characterized in that: It also includes a unloading solenoid valve, which is connected to the hydraulic actuator of the truck crane for unloading the hydraulic actuator, one end of the unloading solenoid valve is connected to the other end of the normally open contact of the alarm relay, and the other end of the unloading solenoid valve is grounded.

3. A truck mounted crane safety protection device according to claim 1, characterized in that: The buzzer is arranged on the turntable support.

4. A truck mounted crane safety protection device according to claim 1, characterized in that: A turntable seat is arranged on the turntable, one end of the limit pin pull rope is connected to the turntable seat, and the other end of the limit pin pull rope is connected to the limit pin.

5. The safety protection device for a truck mounted crane according to claim 1, characterized in that: The buzzer is provided with a manual switch, one end of the manual switch is connected to the other end of the normally open contact of the alarm relay, the other end of the manual switch is connected to one end of the buzzer, and the other end of the buzzer is grounded.

6. A truck mounted crane safety protection device according to claim 1, characterized in that: The limit pin detection switch is a photoelectric proximity switch.

Images