Penetration rod uncoupling device

Abstract

To provide a penetration rod disconnection device which can simply separate a rod used in a penetration testing machine.SOLUTION: A penetration rod disconnection device 100 includes a chuck 5 capable of rotatably holding a penetration rod 4 accompanying driving of a motor 6, and is used in a penetration testing machine that is configured to rotatably penetrate a rod 104a for extension into the ground while sequentially extending the rod 104a for extension by screw connection. The penetration rod disconnection device 100 includes a device body 110 capable of holding the extended rod for extension, and fixing means 120 for regulating rotation of the device body by being fixed to the penetration testing machine 1, and is configured to release screw connection of the rod by driving the motor of the chuck and rotating the penetration rod.SELECTED DRAWING: Figure 6

Description

[Technical Field]

[0001] The present invention relates to a penetration rod disconnecting device for disconnecting a rod used in a penetration test in which a penetration body is inserted into the ground while sequentially adding rods to a penetration rod having a penetration body at the tip of the rod. [Background technology]

[0002] An example of a conventional penetration tester is shown in Patent Document 1. This penetration tester is used to perform a Swedish sounding test, which is an example of a penetration test, and is configured to rotate and penetrate a penetration rod, which is equipped with a screw point, an example of a penetrator, at the tip of the rod, into the ground. The penetration rod is engaged and held in a chuck attached to a lifting platform that can be raised and lowered by a motor, and the screw point at the tip penetrates into the ground as the lifting platform descends. When the lifting platform reaches its lowest point, the operator adds a next rod to the rear end of the rod by screw connection. Then, the penetration rod and chuck are disengaged, the lifting platform is raised, and the platform is lowered again with the rod attached to the chuck engaged and held, thereby penetrating the screw point to an even greater depth. By repeating this rod connection process, the screw point is penetrated to a predetermined depth.

[0003] After the test is completed, the lifting platform is raised with the penetration rod and chuck engaged, allowing the rod to be pulled out of the ground, and the worker releases the rod connection. The rod connection is tightly fastened with a screw, so the worker uses a pipe wrench to release the connection. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2004-92202 Summary of the Invention [Problem to be solved by the invention]

[0005] However, handling a pipe wrench is difficult for beginners and requires skill, so the work of disconnecting the rod has been problematic in terms of workability.

[0006] SUMMARY OF THE INVENTION An object of the present invention is to provide a penetration rod disconnecting tool that can easily disconnect a rod used in a penetration testing machine. [Means for solving the problem]

[0007] The above problem can be solved by a penetration rod disconnecting device used in a penetration testing machine that is equipped with a chuck that can rotatably hold a penetration rod as the motor is driven, and is configured to rotate and penetrate the ground while sequentially extending and extending extension rods via a screw connection, the penetration rod disconnecting device having a device body that can hold the extended extension rod, and fixing means that is fixed to the penetration testing machine and restricts the rotation of the device body, and is configured to drive the chuck motor to rotate the penetration rod, thereby releasing the screw connection of these rods.

[0008] The tool body preferably comprises a hollow chuck shaft having an inner hole through which an extension rod can be inserted, a sleeve that can move back and forth along the chuck shaft and is always biased toward the end of the chuck shaft, a sleeve presser that restricts movement of the sleeve toward the end of the chuck shaft, and a steel ball that is disposed on the chuck shaft and is always supported by the sleeve in a state in which it protrudes into the inner hole of the chuck shaft, and the steel ball is fitted into engagement grooves formed on the outer peripheral surfaces of both ends of the extension rod, and the engagement between the engagement grooves and the steel ball is released by pushing down the sleeve, thereby allowing the tool body to be attached and detached to the extension rod. [Effects of the Invention]

[0009] The penetration rod disconnecting device of the present invention can be simply attached to a penetration testing machine, allowing an operator to easily disconnect the penetration rod without directly touching it with their hands. [Brief explanation of the drawings]

[0010] [Figure 1] FIG. 1 is a perspective view of an automatic penetration testing machine. [Figure 2] FIG. 1 is a side view of an automatic penetration testing machine. [Figure 3] FIG. 3 is an enlarged, partially cutaway cross-sectional view taken along the line AA in FIG. 2. [Figure 4] FIG. 2 is an enlarged, partially cutaway cross-sectional view of a main part showing the configuration of a chuck of an automatic penetration testing machine. [Figure 5] FIG. 2 is a diagram illustrating a configuration of a load sensor. [Figure 6] 1A and 1B are diagrams showing the configuration of a penetration rod uncoupling device of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0011] First, a penetration testing machine in which the penetration rod disconnecting device 100 of the present invention is used will be described based on the drawings. In FIG. 1, 1 is an automatic penetration testing machine, and has a lifting platform 3 that can be raised and lowered along a support 2. This lifting platform 3 is loaded with a weight 3a of a predetermined weight, a rotation motor 6, a chuck 5 that can be rotated by being driven by this rotation motor 6, a penetration rod 4 that can be held by this chuck 5 and rotated integrally, and a lifting motor 8 for raising and lowering the lifting platform 3.

[0012] The penetration rod 4 is composed of a rod 4a and a screw point 4b connected to its tip (lower end). The rod 4a has three engagement grooves 4c at the upper end, dividing the circumference into thirds, and also has three engagement grooves 4d at the lower end, dividing the circumference into thirds.

[0013] As shown in Figure 2, the lifting platform 3 has a sprocket 7 that rotates along a guide chain 2a that is arranged vertically along the support 2, and is configured to rise and fall by rotating this sprocket 7 along the guide chain 2a. The lifting platform 3 and the total weight loaded on the lifting platform 3 are configured so that a load of 1 KN can be applied to the penetration rod 4.

[0014] As shown in Figure 3, the sprocket 7 is connected to a transmission shaft 12 via a planetary gear mechanism 11 so as to rotate integrally with the shaft. A drive gear 13 is attached to the tip of a drive shaft 8a of the lift motor 8, which can rotate forward and backward, so as to rotate integrally with the shaft. An intermediate gear 14 and a transmission gear 15 mesh with the drive gear 13 in this order, so that the drive force of the lift motor 8 is transmitted to the transmission shaft 12.

[0015] The transmission gear 15 is a hollow cylinder with external teeth on its outer periphery. A one-way clutch 16 is press-fitted into the interior of the transmission gear 15 so as to rotate integrally with the transmission gear 15, and is rotatably supported on the transmission shaft 12. This first one-way clutch 16 is configured to transmit the drive of the lifting motor 8 when the lifting motor 8 is driven to rotate the sprocket 7 in the direction in which the lifting platform 3 is to rise (for convenience, this drive is referred to as forward drive). With this configuration, a load determined by (the load based on the total gravity of the lifting platform) - (the lifting force corresponding to the output torque of the lifting motor 8) is applied to the penetration rod 4 as the test load.

[0016] On the other hand, when the lifting motor 8 is driven (for convenience, this drive is referred to as reverse drive), the one-way clutch 16 runs idle. This creates a state in which the drive of the lifting motor 8 is not transmitted to the transmission shaft 12, and the penetration rod 4 can be loaded with 1 kN (maximum test load) based on the mass of the lifting platform.

[0017] A rotary encoder 17 is attached to the transmission shaft 12 and outputs a pulse signal in accordance with the rotation of the sprocket 7. A control unit 50, which will be described in detail later, processes the pulse signal and calculates the penetration amount and penetration speed of the penetration rod 4 based on the amount and speed of elevation of the lifting platform 3.

[0018] The lift motor 8 is an induction motor, and is drive-controlled by an inverter control unit 53. A drive pulley 18 is attached to the rear end of the drive shaft 8a of the lift motor 8 so that the drive pulley 18 can rotate integrally with the lift motor 8. A driven pulley 19 is disposed at a predetermined distance from the drive pulley 18, and an endless belt 20 is wound around these pulleys 18, 19. A rotary encoder 21 is attached to the driven pulley 19 as an acceleration detection means for the lift motor 8, and is configured to detect a pulse signal accompanying the rotation of the drive shaft 8a of the lift motor 8. The pulse signal from the rotary encoder 21 is sent to the inverter control unit 53 and the arithmetic processing unit 51 of the lift motor 8.

[0019] It should be noted that the same function can be realized by using an AC servo motor instead of the induction motor and providing a drive control unit conforming to this.

[0020] As shown in FIG. 4, the chuck 5 comprises a hollow chuck shaft 31 rotatably supported by bearings 45, 46, 47, and 48, and a flange-type sleeve 32 inserted into the chuck shaft 31 via a machine key (not shown). The sleeve 32 is constantly biased upward by a spring 33 and is configured to move while sliding on the outer circumferential surface of the chuck shaft 31. Meanwhile, it rotates circumferentially together with the chuck shaft 31. The chuck shaft 31 is provided with storage holes at positions that divide its outer circumference into thirds, capable of storing steel balls 34. The steel balls 34 fit into the engagement grooves 4c of the penetration rod 4, holding the penetration rod 4. The inner diameter of the upper part of the sleeve 32 is larger than the inner diameter of the chuck shaft 31. Manually pushing the sleeve 32 down against the bias of the spring 33 disengages the steel balls 34 from the engagement grooves 4c of the penetration rod 4. Furthermore, in this state, if the chuck shaft 31 is rotated together with the sleeve 32 and the steel ball 34 is moved to a position where the engagement groove 4c of the penetration rod 4 is not formed, the engagement between the penetration rod 4 and the chuck shaft 31 will be released even if the sleeve 32 is released.

[0021] An annular pressing member 32a is inserted into and fixed to the chuck shaft 31. This pressing member 32a is molded to have the same inner diameter as the sleeve 32 and is configured to press the sleeve 32 from above to prevent it from coming off. The pressing member 32a is disposed so as to protrude from the upper end of the chuck shaft 31, the reason for which will be described later.

[0022] A rotating motor 6 is also mounted on the lifting platform 3. The rotating motor 6 is an induction motor, and is drive-controlled by an inverter control unit 54. A driving sprocket 36 is attached to a drive shaft 6a of the rotating motor 6 via a one-way clutch 35. A driven sprocket 37 is attached to the lower end of the chuck shaft 31, and an endless chain 38 is wound around these sprockets 36, 37 so that the rotational drive of the rotating motor 6 can be transmitted to the chuck shaft 31.

[0023] Here, the screw point 4b at the tip of the penetration rod 4 has a drill shape with one twist per 200 mm of length, as specified in the Japanese Industrial Standards A1221. Therefore, the one-way clutch 35 transmits the drive to the driving sprocket 35 when the rotation motor 6 drives in the direction of screwing the penetration rod 4 into the ground in accordance with the twist of the screw point 4b (hereinafter, for convenience, this drive is referred to as forward drive). On the other hand, when the rotation motor 6 drives in the opposite direction (hereinafter, for convenience, this drive is referred to as reverse drive), it rotates idly, so it is configured not to transmit the drive to the penetration rod 4.

[0024] In addition, a washer-type load cell 39 is inserted into the chuck shaft 31 as an example of a load sensor. As shown in FIG. 5, this washer-type load cell 39 is composed of pressure-receiving portions 41 molded at equal intervals in the circumferential direction on the underside of the sensor body 40, support portions 42 molded at equal intervals in the circumferential direction on the upper surface of the sensor body 40, and a strain gauge 43 attached to the sensor body 40. With this configuration, the thrust load actually applied to the penetration rod 4 is transmitted to the pressure-receiving portion 41 via angular ball bearings 45, 46 and cylindrical roller bearing 47 that support the chuck shaft 31, and accordingly, the support portion 42 serves as a fulcrum for the pressure-receiving plate 44, causing distortion in the sensor body 40. By detecting this distortion with the strain gauge 43, the load applied to the penetration rod 4 can be detected with high accuracy.

[0025] As shown in Figure 2, the control unit 50 that controls the operation and load of the automatic penetration testing machine 1 of the present invention includes an arithmetic processing unit 51, an inverter control unit 53 that drives and controls the lifting motor 8, an inverter control unit 54 that drives and controls the rotation motor, a memory unit 55, and an input unit 56.

[0026] The memory unit 55 stores a torque command value corresponding to the test load, and the calculation processing unit 51 selects the torque command value when a predetermined test load is set. Then, this torque command value is output to the inverter control unit 53, and the lifting motor 8 exerts an upward force according to the torque command value, thereby applying a predetermined test load to the penetration rod 4.

[0027] The inverter control unit 53 controls the drive of the lift motor 8 so that the lift motor 8 is driven by the torque command value output from the calculation processing unit 51. Specifically, the inverter control unit 53 controls the rotation speed and output torque of the lift motor 8 by vector control based on the pulse signal of the rotary encoder 21.

[0028] The calculation processing unit 51 calculates the rotation acceleration of the drive shaft 8 a of the lift motor 8 based on the pulse signal from the rotary encoder 21 of the lift motor 8 .

[0029] Next, the operation of the automatic penetration testing machine 1 will be described. In the automatic penetration testing machine 1, the load applied to the penetration rod 4 is set to six levels: 50N, 150N, 250N, 500N, 750N, and 1KN, in accordance with the Swedish sounding test. For example, if the penetration speed slows down with a 250N load, the load applied to the penetration rod 4 is increased. On the other hand, if the penetration speed increases, the load applied to the penetration rod 4 is decreased. In this way, the command value is changed so that the load increases in the order of 500N, 750N, and 1KN as the penetration speed slows during the penetration stage. Then, when a load of 1KN is applied and the penetration speed slows down, the rotation motor 6 is driven to rotate the chuck 5 and the penetration rod 4 together, and rotational penetration is performed with the load applied.

[0030] During the penetration test, when the lifting platform 3 reaches the ground surface and the entire length of the penetration rod 4 penetrates into the ground, an extension rod 104 a is added to the rear end of the penetration rod 4 .

[0031] The extension rod 104a has a similar configuration to the rod 4a of the penetration rod 4. Both the rod 4a of the penetration rod 4 and the extension rod 104a have female threads at their tips and male threads at their rear ends. This configuration allows the female threads of the extension rod 104a to be threaded into the male threads at the rear end of the penetration rod 4. The penetration rod 4 and the chuck 5 are then disengaged, the lifting platform 3 is raised, and the steel ball 34 of the chuck 5 is fitted into the engagement groove 104c of the extension rod, completing the extension. The lifting platform 3 is then lowered again, allowing the screw point 4b to penetrate to an even greater depth. Repeating this rod connection process allows the screw point 4b to penetrate to a predetermined depth.

[0032] After the test is completed, the extension rod 104a is pulled out of the ground by raising the lifting platform 3 while the extension rod 104a and chuck 5 are engaged. Then, the extension rod 104a is disengaged from the chuck 5, and the lifting platform 3 is lowered to the position of the lower penetration rod 4, and the steel ball 34 of the chuck 5 is fitted into the engagement groove 4c of the rod 4a of the penetration rod 4 (or the engagement groove 104c of the extension rod 104a). Then, the penetration rod disconnecting tool 100 of the present invention is attached to the upper extension rod 104a.

[0033] As shown in FIG. 6, the penetration rod disconnecting device 100 of the present invention comprises a device body 110 and fixing means 120 for fixing the device body 110 to the automatic penetration testing machine 1.

[0034] The tool body 110 has the same configuration as the chuck 5, and is composed of a hollow chuck shaft 131 having a through-hole through which the extension rod 104a can be inserted, and a sleeve 132 fitted onto the chuck shaft 131. The sleeve 132 is constantly biased upward by a spring 133, and is configured to be movable while sliding on the outer circumferential surface of the chuck shaft 131. On the other hand, it is configured to rotate integrally with the chuck shaft 131 in the circumferential direction.

[0035] Furthermore, the chuck shaft 131 of the tool body 110 is provided with storage holes capable of storing steel balls 134 at positions that divide the outer circumference into thirds. These steel balls 134 fit into engagement grooves 104d formed on the outer circumferential surface of the lower end of the extension rod 104a to hold the extension rod 104a. The inner diameter of the upper part of the sleeve 132 is larger than the inner diameter of the chuck shaft 131, and when the sleeve 132 is manually pushed down against the bias of the spring 133, the steel balls 134 are disengaged from the engagement grooves 104d of the extension rod 104a.

[0036] The fixing means 120 is a block member connected to the lower part of the instrument body 110, and has a communication hole 121 that communicates with the through hole of the chuck shaft 131 of the instrument body 110. The fixing means 120 also has a holding groove 122 that can be fitted into a frame 101 provided on the lifting platform 3. For convenience, the frame 101 is not shown in any drawings other than Fig. 6.

[0037] The fixing means 120 has a spigot portion 123 at the opening of the communication hole 121 and is configured so as to be positionable on the upper end of the chuck shaft 31 .

[0038] As for the method of using the above-mentioned penetration rod disconnecting device 1, as described above, after the penetration test is completed, the automatic penetration testing machine 1 performs the predetermined pulling operation, and then the device body 110 of the penetration rod disconnecting device 100 is attached to the engagement groove 104d of the upper extension rod 104a, and the fixing means 120 is fixed to the frame 101 of the lifting platform 3.

[0039] In this state, driving the rotation motor 6 to rotate the chuck 5 rotates the lower penetration rod 4. Meanwhile, the rotation direction of the upper extension rod 104a is fixed by the penetration rod disconnection tool 100, so the threaded portion connecting these rods is unscrewed.

[0040] After the screw engagement is released, when the sleeve 132 is manually pushed down against the force of the spring 133, the steel ball 134 is released from the engagement groove 104d of the extension rod 104a, so in this state, the extension rod 104a is manually rotated, and the engagement groove 104d of the extension rod 104a is rotated and moved to a position where there is no steel ball 134. Even if you release your hand from the sleeve 132, the engagement between the extension rod 104a and the chuck shaft 131 is released, and the extension rod 104a can be removed from the instrument body. The penetration rod connection release tool 1 is removed from the automatic penetration testing machine 1, and the predetermined pulling operation by the automatic penetration testing machine 1 is repeated again, and by using the penetration rod connection release tool 100 each time, the connection of the extension rod 104a can be sequentially released. [Explanation of symbols]

[0041] 1. Automatic penetration testing machine 2 pillars 2a Guide Chain 3 Lift platform 3a weight 4 Penetration Rod 4b screw point 4c Engagement groove 5. Chuck 6 Rotation motor 6a Drive shaft 8 Lifting motor 8a Drive shaft 11 Planetary gear mechanism 12 Transmission shaft 13 Drive gear 14 Intermediate gear 15 Transmission gear 16 One-way clutch 17 Rotary Encoder 18 Drive pulley 19 Driven pulley 20 endless belt 21 Rotary Encoder 31 Chuck axis 32 sleeve 32a holding member 33 Spring 34 steel ball 35 One-way clutch 36 Drive sprocket 37 Driven sprocket 38 Endless Chain 39 Washer type load cell 40 Load cell body 41 Pressure receiving part 42 Support part 43 Strain Gauge 44 Pressure Plate 45,46 Angular contact ball bearings 47,48 Cylindrical roller bearings 50 Control Unit 51 Processing unit 53 Inverter control unit 54 Inverter control unit 55 Storage section 56 Input section 100 Penetration rod disconnecting device 101 frames 104a Extension rod 104c, 104d Engagement groove 110 Equipment body 120 Fixing means 121 Communication hole 122 Retaining groove 123 Inlay part 131 Chuck shaft 132 Sleeve 133 Spring 134 Steel ball

Claims

[Claim 1] A penetration rod disconnection tool used in a penetration testing machine that is equipped with a chuck that can rotatably hold a penetration rod as the motor is driven, and is configured to rotate and penetrate into the ground while sequentially extending and connecting extension rods by screw connection. a tool body capable of holding an extension rod; A penetration rod disconnection device comprising: a fixing means provided in a penetration testing machine and fixing the device body; The instrument body includes: a hollow chuck shaft having an inner hole through which the extension rod can be inserted; a sleeve that is reciprocally movable along the chuck shaft and is always biased toward the end of the chuck shaft; a sleeve holder that restricts movement of the sleeve toward the chuck shaft end; a steel ball disposed on the chuck shaft and always supported by the sleeve in a state of protruding into an inner hole of the chuck shaft, A penetration rod disconnection device characterized in that when the steel balls of the device body are fitted into the engagement grooves formed on the outer peripheral surfaces of both ends of the extension rod and the chuck motor is driven to rotate the penetration rod, the device body holds the extension rod without rotating it, thereby releasing the threaded connection of these rods.

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