Crushing tool and crushing method

Abstract

To provide a crushing tool and a crushing method capable of preventing a reduction in the service life of a tip tool by avoiding sudden wear of the tip tool.SOLUTION: A crushing tool 10 includes: a servo motor 7 that drives a piston 6; a control device 8 that controls the output of the servo motor 7; and a pressure detection device 9 that is disposed between an impact bolt upper part 3a and an impact bolt lower part 3b, and converts the pressure between the impact bolt upper part 3a and the impact bolt lower part 3b into a pressure signal. The control device 8 increases the output of the servo motor 7 continuously or stepwise while monitoring the pressure signal, and decreases the output of the servo motor 7 when the signal strength of the pressure signal exceeds a predetermined threshold.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a crushing tool.

Background Art

[0002] In operations such as tunnel excavation, rock breaking, and mining, a crushing tool in which a chisel is attached to the tip of a breaker, which is an impact tool, is used. As a document disclosing the prior art of a rock drilling device, which is a type of crushing tool, there is, for example, Patent Document 1.

[0003] Patent Document 1 discloses "a rock drilling device including a breaker having a chisel that contacts an object to be crushed, a planar load detection unit that measures a planar load, which is a load in a direction orthogonal to the axial direction of the breaker, a breaker support mechanism that supports the breaker so as to be movable in a direction orthogonal to the axial direction, and a posture change mechanism that changes the posture of the breaker with respect to the object to be crushed based on the distribution of the planar load on the entire circumference of the breaker measured by the planar load detection unit."

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] In general, chisels (tip tools) of crushing tools often use quenched steel. Such crushing tools are used for objects with a hardness or fracture toughness value lower than that of the tip tool. On the other hand, there is a desire to use a crushing tool even when crushing an object having unknown physical properties and composed of various compositions and structures. However, when the object to be crushed contains a material with a high hardness or fracture toughness value such as metal, continuous impact on the material may cause the tip tool to rapidly wear, and the life of the tip tool may be significantly reduced.

[0006] The present invention has been made in view of the above problems, and an object thereof is to provide a crushing device and a crushing method capable of preventing a reduction in the life of a tip tool by avoiding rapid wear of the tip tool.

Means for Solving the Problems

[0007] In order to achieve the above object, the present invention provides a crushing device including a cylindrical casing, a tip tool that contacts an object to be crushed, an impact bolt that is attached to a base end portion of the tip tool and is slidably disposed within the casing, a striker that is slidably disposed within the casing and applies an impact force to the impact bolt, a piston that is slidably disposed within the casing and forms an air spring with the striker, and a motor that drives the piston. The motor is a servo motor. The impact bolt has an upper portion of the impact bolt and a lower portion of the impact bolt. The crushing device includes a control device that controls the output of the servo motor, and a pressure detection device that is disposed between the upper portion of the impact bolt and the lower portion of the impact bolt and converts the pressure between the upper portion of the impact bolt and the lower portion of the impact bolt into a pressure signal. The control device continuously or stepwise increases the output of the servo motor while monitoring the pressure signal, and decreases the output of the servo motor when the signal intensity of the pressure signal exceeds a predetermined threshold value.

[0008] Further, the present invention provides a crushing method for crushing an object to be crushed, including a first step of continuously or stepwise increasing the impact force of a tip tool that contacts the object to be crushed while monitoring the impact force of the tip tool, and a second step of decreasing the impact force of the tip tool when the impact force of the tip tool exceeds a predetermined threshold value.

Effects of the Invention

[0009] According to the present invention, when the object to be crushed does not break even if the impact force exceeds a certain level, the output of the servo motor that generates the impact force of the tip tool decreases. As a result, it is possible to avoid rapid wear of the tip tool by continuously striking a material having a hardness or fracture toughness value higher than that of the tip tool, and thus it is possible to prevent a decrease in the life of the tip tool.

Brief Description of the Drawings

[0010]

Figure 1

Figure 2

Figure 3

Embodiments for Carrying Out the Invention

[0011] Hereinafter, embodiments of the present invention will be described with reference to the drawings. In each figure, the same reference numerals are given to equivalent elements, and duplicate descriptions will be omitted as appropriate.

[0012] FIG. 1 is a configuration diagram of a chisel device which is a crushing tool in the present embodiment. In FIG. 1, the chisel device 10 includes a cylindrical casing 1, a chisel 2 which is a tip tool that contacts the object to be crushed, an impact bolt 3 which is attached to the base end portion of the chisel 2 and is slidably disposed within the casing 1, a striker 4 which is slidably disposed within the casing 1 and applies an impact force to the impact bolt 3, a piston 6 which is slidably disposed within the casing 1 and forms an air spring 5 between the piston 6 and the striker 4, a servo motor 7 which drives the piston 6, and a control device 8 which controls the output of the servo motor 7.

[0013] When the piston 6 is driven downward, the air spring 5 is compressed. Due to the expansion of the compressed air spring 5, the striker 4 is driven downward and collides with the impact bolt 3. The kinetic energy of the striker 4 transmitted to the impact bolt 3 is transmitted to the chisel 2 and becomes the striking force of the chisel 2. The striker 4 moves upward by the reaction force when it collides with the impact bolt 3. By matching the timing when the striker 4 moves upward and the timing when the piston 6 is driven downward and increasing the pressure of the air spring 5, it becomes possible to generate a strong striking force.

[0014] A general chisel device is equipped with a motor that does not have a control mechanism for output (rotation speed or torque) as a power source for the piston 6. In contrast, the chisel device 10 in the present embodiment is equipped with a servo motor 7 capable of controlling the output (rotation speed or torque), and the striking force of the chisel 2 can be adjusted by controlling the output of the servo motor 7.

[0015] The impact bolt 3 is divided into two parts vertically, and has an impact bolt upper part 3a and an impact bolt lower part 3b. A pressure detection device 9 for measuring the striking force (including the reaction force) of the chisel 2 is arranged between the impact bolt upper part 3a and the impact bolt lower part 3b.

[0016] The pressure detection device 9 is composed of a plurality of load cells 9a, 9b, 9c. The pressure detection device 9 in the present embodiment is composed of three load cells 9a, 9b, 9c, but the number of load cells is not limited to this. The load cells 9a, 9b, 9c convert the striking force (including the reaction force) of the chisel 2 into a pressure signal and output it to the control device 8. The control device 8 controls the output (rotation speed or torque) of the servo motor 7 according to the pressure signal output from the load cells 9a, 9b, 9c. The control device 8 is composed of a microcomputer or the like equipped with an arithmetic device such as a CPU, a storage device such as a ROM and a RAM, and an input / output interface for performing signal input / output with external devices.

[0017] By configuring the pressure detection device 9 with a plurality of load cells 9a, 9b, and 9c, even when the maximum pressure that each load cell 9a, 9b, 9c can detect individually is lower than the impact force of the chisel 2, by summing the pressure signals of each load cell 9a, 9b, 9c, it becomes possible to accurately measure the impact force of the chisel 2. Further, the load cells 9a, 9b, 9c are arranged at equal intervals in the circumferential direction of the casing 1. By arranging the three load cells 9a, 9b, 9c in this way so as not to be in a straight line, it becomes possible to prevent play between the upper part 3a and the lower part 3b of the impact bolt.

[0018] Figure 2 is a flowchart showing a crushing method using the chisel device 10. Hereinafter, each step will be described in order.

[0019] First, the chisel 2 is moved to the first impact point (step S1). Step S1 is performed by an operator or a robot.

[0020] Following step S1, the control device 8 drives the servo motor 7 with a low output (step S2). As a result, the impact starts with a weak impact force.

[0021] Following step S2, the control device 8 determines whether the intensity of the pressure signal input from the pressure detection device 9 exceeds a predetermined threshold value (step S3). The predetermined threshold value mentioned here is set based on an impact force at which the chisel 2 does not undergo rapid wear.

[0022] If the determination result in step S3 is YES, the control device 8 stops the output of the servo motor 7 (step S6) and proceeds to step S7 described later. As a result, if the crushing object does not break even when exceeding a certain impact force, the impact of the tip tool 2 stops, so it becomes possible to avoid rapid wear of the tip tool 2. Note that it is not always necessary to stop the output of the servo motor 7, and it may be sufficient to simply reduce the output.

[0023] If the determination result in step S3 is NO, the control device 8 determines whether the intensity of the pressure signal has decreased (step S4). Step S4 is a process of determining whether the object to be crushed has been crushed at the current impact point. The relationship between the number of impacts and the impact force when the object to be crushed is crushed is shown in FIG. 3. When the object to be crushed is crushed, the impact force of the chisel 2 (the intensity of the pressure signal from the load cells 9a, 9b, 9c) rapidly decreases. By detecting this decrease, it becomes possible to instantaneously detect that the object to be crushed has been crushed even among the disturbances during the impact.

[0024] If the determination result in step S4 is NO, the control device 8 slightly increases the output of the servo motor 7 (step S5) and returns to step S3. As a result, when the object to be crushed is not crushed, the impact force of the chisel 2 gradually (continuously or stepwise) increases.

[0025] If the determination result in step S4 is YES, it is determined whether there is a next impact point (step S7). Step S7 is performed by an operator or a robot. If the determination result in step S7 is YES, the chisel 2 is moved to the next impact point (step S8) and the process returns to step S2. As a result, since the output of the servo motor 7 decreases immediately after the object to be crushed is crushed at the current impact point, it becomes possible to suppress the power consumption of the servo motor 7.

[0026] If the determination result in step S4 is NO, the flow is terminated.

[0027] (Summary) In this embodiment, a crushing device 10 includes a cylindrical casing 1, a tip tool 2 that contacts an object to be crushed, an impact bolt 3 attached to the base end portion of the tip tool 2 and slidably disposed within the casing 1, a striker 4 slidably disposed within the casing 1 that applies an impact force to the impact bolt 3, a piston 6 slidably disposed within the casing 1 that forms an air spring 5 with the striker 4, and a motor 7 that drives the piston 6. The motor 7 is a servo motor 7. The impact bolt 3 has an upper impact bolt 3a and a lower impact bolt 3b. The crushing device 10 includes a control device 8 that controls the output of the servo motor 7, and a pressure detection device 9 disposed between the upper impact bolt 3a and the lower impact bolt 3b that converts the pressure between the upper impact bolt 3a and the lower impact bolt 3b into a pressure signal. The control device 8 continuously or stepwise increases the output of the servo motor 7 while monitoring the pressure signal, and decreases the output of the servo motor 7 when the signal intensity of the pressure signal exceeds a predetermined threshold value. Further, in this embodiment, in a crushing method for crushing an object to be crushed, a first step (steps S3, S4, S5) of continuously or stepwise increasing the impact force of the tip tool 2 while monitoring the impact force of the tip tool 2 that contacts the object to be crushed, and a second step (step S6) of decreasing the impact force of the tip tool 2 when the impact force of the tip tool 2 exceeds a predetermined threshold value are provided.

[0028] According to the present embodiment configured as described above, when a material having a high hardness or fracture toughness value cannot be crushed even when struck with an impact force equal to or greater than a certain level, the impact force of the tip tool 2 decreases. Thereby, it is possible to avoid rapid wear of the tip tool 2 due to continuously striking a material having a high hardness or fracture toughness value, and thus it is possible to prevent a reduction in the life of the tip tool.

[0029] In addition, the control device 8 in the present embodiment monitors the pressure signal while continuously or stepwise increasing the output of the servo motor 7, and stops the servo motor 7 when the signal intensity of the pressure signal exceeds the predetermined threshold value. Further, in the crushing method in the present embodiment, in the second step (step S6), when the impact force of the tip tool 2 exceeds the predetermined threshold value, the impact of the tip tool 2 is stopped. Thereby, when a material with high hardness or fracture toughness value cannot be crushed even when struck with an impact force equal to or greater than a certain level, the impact of the tip tool 2 is stopped, so that it is possible to more reliably avoid rapid wear of the tip tool 2.

[0030] In addition, the control device 8 in the present embodiment monitors the pressure signal while continuously or stepwise increasing the output of the servo motor 7, and decreases the output of the servo motor 7 when the signal intensity of the pressure signal decreases without exceeding the predetermined threshold value. Further, the crushing method in the present embodiment includes a third step (steps S4, S2) of decreasing the impact force of the tip tool 2 when the impact force of the tip tool 2 decreases without exceeding the predetermined threshold value. Thereby, since the output of the servo motor 7 decreases immediately after the object to be crushed is crushed, it is possible to suppress the power consumption of the servo motor 7.

[0031] In addition, the pressure detection device 9 in the present embodiment is composed of a plurality of load cells 9a, 9b, 9c, and the control device 8 calculates the total value of the signal intensities output from the plurality of load cells 9a, 9b, 9c as the signal intensity of the pressure signal. Thereby, even when the maximum pressure that each load cell 9a, 9b, 9c can detect individually is lower than the impact force of the tip tool 2, by summing the pressure signals of each load cell 9a, 9b, 9c, it is possible to accurately measure the impact force of the tip tool 2.

[0032] Also, the pressure detection device 9 in this embodiment is composed of three load cells 9a, 9b, and 9c, and the three load cells 9a, 9b, and 9c are arranged so as not to be aligned on the same straight line. Thereby, it becomes possible to prevent the play between the upper part 3a and the lower part 3b of the impact bolt.

[0033] Note that the present invention is not limited to the above-described embodiments, and various modifications are included. For example, the above-described embodiments are shown for easily explaining the present invention, and are not necessarily limited to those having all the configurations described.

Explanation of Signs

[0034] 1... casing, 2... chisel (tip tool), 3... impact bolt, 3a... upper part of impact bolt, 3b... lower part of impact bolt, 4... striker, 5... air spring, 6... piston, 7... servo motor, 8... control device, 9... pressure detection device, 9a, 9b, 9c... load cells, 10... chisel device (crushing tool).

Claims

1. A cylindrical casing, a tip tool that contacts the object to be crushed, an impact bolt attached to the base end of the tip tool and slidably disposed within the casing, a striker slidably disposed within the casing and applying an impact force to the impact bolt, a piston slidably disposed within the casing and forming an air spring with the striker, and a motor for driving the piston, in a crushing device, wherein the motor is a servo motor, the impact bolt has an upper impact bolt and a lower impact bolt, the crushing device, comprises a control device for controlling the output of the servo motor, and a pressure detection device disposed between the upper impact bolt and the lower impact bolt for converting the pressure between the upper impact bolt and the lower impact bolt into a pressure signal, wherein the control device continuously or stepwise increases the output of the servo motor while monitoring the pressure signal, and decreases the output of the servo motor when the signal intensity of the pressure signal exceeds a predetermined threshold value characterizing the crushing device.

2. In the crushing device according to Claim 1, the control device monitors the pressure signal while continuously or stepwise increasing the output of the servo motor, and stops the servo motor when the signal intensity of the pressure signal exceeds the predetermined threshold value characterizing the crushing device.

3. In the crushing device according to Claim 1, the control device continuously or stepwise increases the output of the servo motor while monitoring the pressure signal, and decreases the output of the servo motor when the signal intensity of the pressure signal decreases without exceeding the predetermined threshold value characterizing the crushing device.

4. In the crushing device according to Claim 1, the pressure detection device is composed of a plurality of load cells, and the control device calculates the total value of the signal intensities respectively output from the plurality of load cells as the signal intensity of the pressure signal characterizing the crushing device.

5. In the crushing device according to Claim 4, the pressure detection device is composed of three load cells, and the three load cells are arranged so as not to be aligned on the same straight line characterizing the crushing device.

6. In a crushing method for crushing an object to be crushed, A first step of continuously or stepwise increasing the impact force of the tip tool that contacts the object to be crushed while monitoring the impact force of the tip tool; A second step of reducing the impact force of the tip tool when the impact force of the tip tool exceeds a predetermined threshold value A crushing method characterized by the above. **Claim 7** In the crushing method according to claim 6, In the second step, when the impact force of the tip tool exceeds the predetermined threshold value, the impact of the tip tool is stopped A crushing method characterized by the above. **Claim 8** In the crushing method according to claim 6, When the impact force of the tip tool decreases without exceeding the predetermined threshold value, a third step of reducing the impact force of the tip tool is provided A crushing method characterized by the above.

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