Force transmission device

Abstract

To provide a force transmission device that allows the force from pressing means to be easily transmitted to a rock bolt even if a center line of a force transmission shaft of the pressing means and the center line of the rock bolt are not located on the same straight line, and can improve the work efficiency of inserting the rock bolt into a hole.SOLUTION: A force transmission device of the present invention is provided between pressing means (rock drill) and a rock bolt and transmits the force from the pressing means to the rock bolt when driving the rock bolt comprises a rear transmission shaft whose rear end is attached to the pressing means, a front transmission shaft 13 with the rock bolt attached to its front end, an intermediate transmission shaft 12 provided between the rear transmission shaft and the front transmission shaft, rear connecting means for connecting the front end of the rear transmission shaft and the rear end of the intermediate transmission shaft, and front connecting means 16 connecting the front end of the intermediate transmission shaft and the rear end of the front transmission shaft. The rear connecting means and the front connecting means include a sliding mechanism 6 and a limiting mechanism 7 that limits the sliding range of the sliding mechanism.SELECTED DRAWING: Figure 4

Description

[Technical Field]

[0001] The present invention relates to a force transmission device that is provided between a pressing means and a lock bolt and transmits force from the pressing means to the lock bolt. [Background technology]

[0002] A known force transmission device is provided between a rock drill (drifter) as a pressing means and a rock bolt to transmit the force from the rock drill to the rock bolt. The force transmission device comprises a rear transmission shaft whose rear end is attached to the rock drill, a front transmission shaft whose front end is attached to the rock bolt, and an intermediate transmission shaft provided between the rear transmission shaft and the front transmission shaft, with the front end of the rear transmission shaft and the rear end of the intermediate transmission shaft connected via a first bend, and the front end of the intermediate transmission shaft and the rear end of the front transmission shaft connected via a second bend (see Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Special Publication No. 2008-540874 Summary of the Invention [Problem to be solved by the invention]

[0004] However, according to the force transmission device disclosed in Patent Document 1, the first bending portion and the second bending portion are made of rubber and are configured to bend, so when the first bending portion or the second bending portion is bent, there is a problem in that the elastic action of the rubber makes it difficult to transmit the force from the rock drill in the desired direction. In other words, when the first bent portion or the second bent portion becomes bent and the center line of the rock drill's shank rod (the force transmission axis of the pressing means) and the center line of the rock bolt are not positioned on the same straight line, the force from the rock drill is not easily transmitted to the rock bolt, making it difficult to insert the rock bolt into the hole, resulting in poor work efficiency. The present invention provides a force transmission device that makes it easier to transmit force from the pressing means to the lock bolt even if the center line of the force transmission shaft of the pressing means and the center line of the lock bolt are not positioned on the same straight line, thereby improving the work efficiency of inserting the lock bolt into a hole. [Means for solving the problem]

[0005] The force transmission device according to the present invention is a force transmission device that is provided between a pressing means and a rock bolt to transmit force from the pressing means to the rock bolt when the rock bolt is driven from a tunnel cavity into the natural ground, and includes a rear transmission shaft having a rear end attached to the pressing means, a front transmission shaft having a rock bolt attached to its front end, an intermediate transmission shaft provided between the rear transmission shaft and the front transmission shaft, rear connecting means that connects the front end of the rear transmission shaft to the rear end of the intermediate transmission shaft, and front connecting means that connects the front end of the intermediate transmission shaft to the rear end of the front transmission shaft, and the rear connecting means is provided between the center line of the rear transmission shaft and the intermediate transmission shaft and a limiting mechanism that limits the sliding range of the sliding mechanism so that the intersection angle between the center line of the intermediate transmission shaft and the center line of the front transmission shaft does not exceed a predetermined angle. The front connecting means includes a sliding mechanism between the front end of the intermediate transmission shaft and the rear end of the front transmission shaft that operates to allow the intersection angle between the center line of the intermediate transmission shaft and the center line of the front transmission shaft to exceed a predetermined angle. The sliding mechanism is configured by a spherical sliding mechanism in which a spherical surface provided at one end of one transmission shaft slides on a spherical seat provided at one end of the other transmission shaft, and the spherical surface is configured by a semi-spherical spherical surface formed so as to protrude from a plate surface of a plate portion provided at one end of one transmission shaft, and the plate surface of the plate portion is positioned on a plane perpendicular to the center line of one transmission shaft, and the spherical seat is configured by a semi-spherical concave surface formed so as to be recessed from the plate surface of the plate portion provided at one end of the other transmission shaft and in full contact with the spherical surface, and the plate surface of the plate portion is positioned on a plane perpendicular to the center line of the other transmission shaft. The limiting mechanism is positioned on a plane perpendicular to the center line, and is configured so that when the center line of one transmission shaft coincides with the center line of the other transmission shaft and the spherical surface is in contact with the spherical seat, the plate surface of the plate part of one transmission shaft and the plate surface of the plate part of the other transmission shaft face each other in parallel at a predetermined distance, and when the intersection angle between the center line of one transmission shaft and the center line of the other transmission shaft reaches a predetermined angle, the periphery of the plate surface of one plate part comes into contact with the plate surface of the other plate part, restricting the intersection angle so that it does not exceed the predetermined angle. It is characterized by the fact that Furthermore, the force transmission device according to the present invention is a force transmission device that is provided between a pressing means and a rock bolt to transmit force from the pressing means to the rock bolt when the rock bolt is driven from a tunnel cavity into the natural ground, and includes a rear transmission shaft having a rear end attached to the pressing means, a front transmission shaft having a rock bolt attached to its front end, and a connecting means that connects the front end of the rear transmission shaft and the rear end of the front transmission shaft, and the connecting means includes a sliding mechanism between the front end of the rear transmission shaft and the rear end of the front transmission shaft that operates to allow the center lines of the rear transmission shaft and the front transmission shaft to intersect, and a limiting mechanism that limits the sliding range of the sliding mechanism so that the intersection angle between the center line of the rear transmission shaft and the center line of the front transmission shaft does not exceed a predetermined angle. The sliding mechanism is configured by a spherical sliding mechanism in which a spherical surface provided at one end of one transmission shaft slides on a spherical seat provided at one end of the other transmission shaft, and the spherical surface is configured by a semi-spherical spherical surface formed so as to protrude from a plate surface of a plate portion provided at one end of one transmission shaft, and the plate surface of the plate portion is positioned on a plane perpendicular to the center line of one transmission shaft, and the spherical seat is configured by a semi-spherical concave surface formed so as to be recessed from the plate surface of the plate portion provided at one end of the other transmission shaft and in full contact with the spherical surface, and the plate surface of the plate portion is positioned on a plane perpendicular to the center line of the other transmission shaft. The limiting mechanism is positioned on a plane perpendicular to the center line, and is configured so that when the center line of one transmission shaft coincides with the center line of the other transmission shaft and the spherical surface is in contact with the spherical seat, the plate surface of the plate part of one transmission shaft and the plate surface of the plate part of the other transmission shaft face each other in parallel at a predetermined distance, and when the intersection angle between the center line of one transmission shaft and the center line of the other transmission shaft reaches a predetermined angle, the periphery of the plate surface of one plate part comes into contact with the plate surface of the other plate part, restricting the intersection angle so that it does not exceed the predetermined angle. It is characterized by the fact that Also, In each connecting means, a bolt through-hole is formed on the peripheral side of the plate surface of one of the plate portions, penetrating one of the plate portions, and a bolt through-hole is formed on the peripheral side of the plate surface of the other plate portion, penetrating the other plate portion. The shank of a bolt that is passed through the bolt through-hole of one of the plate portions and the bolt through-hole of the other plate portion passes through the hollow part of the compression coil spring, and a nut is fastened from the tip side of the shank of the bolt, so that the compression coil spring is attached between the other plate portion and the nut. The present invention is characterized by being configured as follows. According to the force transmission device of the present invention, even if the center line of the force transmission shaft of the pressing means and the center line of the lock bolt are not positioned on the same straight line, the force from the pressing means is easily transmitted to the lock bolt, thereby improving the work efficiency of inserting the lock bolt into the hole. Furthermore, the front end of the front transmission shaft is characterized by being equipped with a water injection head to which the rear end of the steel pipe expansion type friction rock bolt is attached. This prevents excessive force from being applied to the steel pipe expansion type friction rock bolt, allowing the steel pipe expansion type friction rock bolt to be inserted straight into the hole, and enabling the installation work of the steel pipe expansion type friction rock bolt to be carried out accurately and reliably. The device is also characterized by having a water intake port and a swivel that is attached to the transmission shaft so as not to rotate together with the transmission shaft, and supplies water taken in from the water intake port to the water injection head through a water passage provided in the transmission shaft.Therefore, even when the shaft of the force transmission device is rotated, the water supply hose connected to the water intake port will not become entangled in the shaft. [Brief explanation of the drawings]

[0006] [Figure 1] A process diagram showing the steps for installing rock bolts. [Figure 2]1A and 1B are explanatory diagrams of a rock bolt, in which (a) is a side view of the rock bolt, (b) is a cross-sectional view taken along the line AA in (a), and (c) is a diagram showing the expansion change of the steel pipe part of the rock bolt. [Figure 3] 1A and 1B are diagrams showing a force transmission device, in which FIG. 1A is a plan view of the force transmission device, and FIG. 1B is a side view of the force transmission device. [Figure 4] FIG. [Figure 5] FIG. [Figure 6] FIG. 10 is an exploded view showing the intermediate transmission shaft and the swivel. [Figure 7] FIG. [Figure 8] FIG. 10 is a perspective view showing a state in which a washer is removably attached to the washer holding means. [Figure 9] FIG. 4 is a perspective view showing the washer holding means and the washer separately. DETAILED DESCRIPTION OF THE INVENTION

[0007] Embodiment 1 As shown in Figure 1, the force transmission device 1 of embodiment 1 is a device that is installed between a rock drill (drifter) 3 as a pressing means and a rock bolt 2 when driving the rock bolt 2 from a tunnel cavity T into the ground M using a face drilling machine such as a Drill Jumbo (registered trademark), and transmits force from the rock drill 3 to the rock bolt 2. The face drilling machine is provided with, for example, multiple booms, and a drilling device 4 is provided at the tip of at least one boom 31, and a rock bolt mounting device 5 is provided at the tip of at least one boom 32. The boom is a rod-shaped structure that has the functions of raising, lowering, extending, and rotating by means of an actuator such as a hydraulic cylinder.

[0008] A guide cell 33 is provided on the tip side of the booms 31, 32. For example, the guide cell 33 has a guide and a carriage 35 that can slide along the guide . The rock drill 3 is fixed on a carriage 35, and the carriage 35 and the rock drill 3 are configured to be able to move back and forth on a guide 34 by driving a carriage drive mechanism not shown.

[0009] As shown in FIG. 1( a ), the drilling device 4 is configured to include a rock drill 3 and a drilling rod 36 connected to the tip side of a shank rod 30 of the rock drill 3 . As shown in Figure 1(b), the rock bolt mounting device 5 is configured to include a rock drill 3, a force transmission device 1 of embodiment 1 connected to the tip side of the shank rod 30 of the rock drill 3, and a washer holding means 8.

[0010] The booms 31 and 32 are devices that move the drilling device 4 and the rock bolt fastening device 5 to a desired position and maintain them in a desired attitude. That is, the boom 31 is driven to move the drilling device 4 to the desired position and maintain it in the desired attitude, and then the rock drill 3 is moved toward the wall W of the tunnel cavity T, and the rock drilling bit 37 attached to the tip of the drilling rod 36 is moved to the drilling position. Then, as shown in Figure 1(a), the carriage drive mechanism is driven while the rock drill 3 is driven, and the drilling rod 36 is pressed while applying a rotational force and an impact force to it, thereby drilling a hole H from the wall W into the natural ground M for inserting a rock bolt 2.

[0011] After attaching the rock bolt 2 to the tip of the force transmission device 1 connected to the tip of the shank rod 30 of the rock drill 3, the boom 32 is driven to move the rock bolt attaching device 5 to the desired position and maintain the desired posture (see Figure 1(b)). The rock drill 3 is then moved forward in a direction approaching the hole H to insert the rock bolt 2 into the hole H (see Figures 1(c), (d), and (e)). Note that it is preferable not to apply a rotational force or impact force to the rock bolt 2 when inserting it into the hole H. However, if there is a large resistance when inserting the rock bolt 2 into the hole H, the rock bolt 2 may be inserted into the hole H while impacting or rotating the rock bolt 2 with the rock drill 3, as necessary.

[0012] As shown in FIG. 2, the rock bolt 2 is, for example, a steel pipe expansion type friction rock bolt. As shown in Figure 2(a), the rock bolt 2 is composed of a steel pipe section 20, a front end sealing section 21 that seals the front end of the steel pipe section 20, and a rear end sealing section 22 that seals the rear end of the steel pipe section 20.

[0013] The steel pipe portion 20 has, for example, a hot-dip zinc, aluminum, and magnesium alloy plating layer on the surface, and is formed into a cross-sectional shape as shown in FIG. 2(b). That is, in the initial state before expansion deformation, the steel pipe section 20 is composed of a deformed steel pipe formed by deforming both ends (both radial ends of the pipe) of a flat cross section of a steel pipe material having a flat cross section perpendicular to the extension direction of the pipe so that the cross-sectional outer shape becomes close to circular, as shown in Figures 2(b) and (c), and is configured so that when water pressure is applied inside the deformed steel pipe, it expands and deforms into a circular steel pipe shape.

[0014] The tip side sealing portion 21 includes a tip side sealing sleeve 23 that covers the outer periphery of the tip side of the steel pipe portion 20 and seals the tip opening of the steel pipe portion 20, and a conical tip cone 24 provided at the tip of the tip side sealing sleeve 23. The tip cone 24 is provided integrally with or separately from the tip side sealing sleeve 23. Note that the tip side sealing portion 21 may not necessarily include the tip cone 24.

[0015] The rear-end sealing section 22 comprises a small-diameter sleeve 25 that covers the outer periphery of the rear end side of the steel pipe section 20, and a water injection sleeve 26 that covers the outer periphery of the rear end side of the steel pipe section 20 and seals the rear-end opening of the steel pipe section 20. The water injection sleeve 26 is located rearward of the small-diameter sleeve 25 and has an outer diameter larger than that of the small-diameter sleeve 25. An annular groove 27 is formed in the outer peripheral surface on the central side in the direction along the center line of the sleeve, and is formed in the shape of a ring that goes around the outer peripheral surface. A water injection hole 28 is provided that penetrates from the bottom of the annular groove 27 to the inner surface of the water injection sleeve 26 and penetrates from the outer surface to the inner surface of the steel pipe section 20 located inside the water injection sleeve 26.

[0016] That is, the steel pipe section 20 is configured so that it expands from a deformed steel pipe shape and deforms into a circular steel pipe shape, as shown in Figure 2(c), due to the pressure of water injected into the inside of the steel pipe section 20 through the water injection head 50, annular groove 27, and water injection hole 28 described below. In addition, the front end sealing portion 21 and the rear end sealing portion 22 are formed from a material (e.g., synthetic resin, etc.) that is not deformed by the water pressure that transforms the steel pipe portion 20 from a deformed steel pipe shape to a circular steel pipe shape.

[0017] As shown in FIG. 3, the force transmission device 1 according to the first embodiment is configured to include a rear transmission shaft 11, an intermediate transmission shaft 12, a front transmission shaft 13, a rear connecting means 15 that connects the front end of the rear transmission shaft 11 to the rear end of the intermediate transmission shaft 12, a front connecting means 16 that connects the front end of the intermediate transmission shaft 12 to the rear end of the front transmission shaft 13, and a swivel 40.

[0018] The rear connecting means 15 and the front connecting means 16 each include a sliding mechanism 6 and a limiting mechanism 7 .

[0019] As shown in Figures 4 and 5, the sliding mechanism 6 is composed of a spherical surface 63 formed on one end of one transmission shaft 61 of the transmission shafts arranged in the front and rear, and a spherical seat 64 which is a recess formed on one end of the other transmission shaft 62 of the transmission shafts arranged in the front and rear and comes into contact with the spherical surface 63, and is configured so that the spherical surface 63 and the spherical seat 64 come into contact and slide. That is, the sliding mechanism 6 is configured by a spherical sliding mechanism in which a spherical surface 63 provided at one end of one transmission shaft 61 and a spherical seat 64 provided at one end of the other transmission shaft 62 slide on each other. 4 and 5 show a case where one transmission shaft 61 is the front transmission shaft 13 and the other transmission shaft 62 is the intermediate transmission shaft 12, that is, the front connecting means 16.

[0020] The spherical surface 63 is configured as a semispherical spherical surface formed to protrude from a plate surface (rear plate surface) 65a of a plate portion 65 provided at one end of one transmission shaft 61 (for example, the rear end of the front transmission shaft 13). The spherical seat 64 is formed to be recessed from the plate surface (front plate surface) 66a of the plate portion 66 provided at one end of the other transmission shaft 62 (for example, the front end portion of the intermediate transmission shaft 12) and is composed of a hemispherical concave surface that is in full contact with the spherical surface 63. The plate portions 65 and 66 are formed, for example, from circular plate portions having circular plate surfaces.

[0021] That is, the plate surface 65a of the plate portion 65 is positioned on a plane perpendicular to the center line 61C of one of the transmission shafts 61, and the spherical surface 63 is composed of a hemispherical spherical surface formed to protrude from the plate surface 65a, and is configured so that the center of the spherical surface 63 is positioned on the center line 61C of one of the transmission shafts 61. Furthermore, the plate surface 66a of the plate portion 66 is positioned on a plane perpendicular to the center line 62C of the other transmission shaft 62, and the spherical seat 64 is configured as a hemispherical concave surface recessed from the plate surface 66a, with the center of the spherical seat 64 positioned on the center line 62C of the other transmission shaft 62.

[0022] The limiting mechanism 7 is configured as follows. First, as shown in FIG. 5, when the center line 61C of one transmission shaft 61 and the center line 62C of the other transmission shaft 62 are aligned and the spherical surface 63 and the spherical seat 64 are in contact with each other, the plate surface 65a of the plate portion 65 of one transmission shaft 61 and the plate surface 66a of the plate portion 66 of the other transmission shaft 62 are configured to face each other in parallel with a predetermined distance S between them.

[0023] Furthermore, bolt holes (not shown) that penetrate the plate portion 65 are formed on the peripheral edge side of the plate surface 65a of one plate portion 65 at four locations spaced 90° apart in the circumferential direction around the center line 61C of one transmission shaft 61. Similarly, bolt holes (not shown) are also formed in the other plate portion 66. Then, for example, the shank of the bolt 70 is passed through the bolt-through hole of one plate portion 65 and the bolt-through hole of the other plate portion 66, and then the shank of the bolt 70 is passed through the spring hollow portion of the compression coil spring 72, and then a nut 73 is fastened from the tip side of the shank of the bolt 70, thereby forming a state in which the compression coil spring 72 is attached between the other plate portion 66 and the nut 73.

[0024] Since the limiting mechanism 7 is provided, when the intersection angle α between the center line 61C of one transmission shaft 61 and the center line 62C of the other transmission shaft 62 reaches a predetermined angle, the peripheral edge 65b of the plate surface (rear plate surface) 65a of one plate portion 65 comes into contact with the plate surface (front plate surface) 66a of the other plate portion 66, thereby limiting the intersection angle α so that it does not become larger than the predetermined angle, as shown in Figure 4. That is, a limiting mechanism 7 is provided that limits the sliding range of the sliding mechanism 6 so that the intersection angle α between the center line 61C of one transmission shaft 61 and the center line 62C of the other transmission shaft 62 does not exceed a predetermined angle. The limiting mechanism 7 is configured so that the intersection angle α does not exceed a predetermined angle of, for example, 5°.

[0025] In other words, the limiting mechanism 7 is configured such that, when the spherical surface 63 and the spherical seat 64 are in contact with each other, the plate surface (rear plate surface) 65a of the plate portion 65 of one transmission shaft 61 and the plate surface (front plate surface) 66a of the plate portion 66 of the other transmission shaft 62 face each other in parallel at a predetermined distance S (see Figure 5), and when the intersection angle α between the center line 61C of one transmission shaft 61 and the center line 62C of the other transmission shaft 62 becomes a predetermined angle, the peripheral edge 65b of the plate surface 65a of one plate portion 65 and the plate surface 66a of the other plate portion 66 come into contact with each other, thereby limiting the intersection angle α so that it does not become larger than the predetermined angle.

[0026] Although detailed illustration of the rear connecting means 15 is omitted, the rear connecting means 15 is also configured in the same manner as the front connecting means 16 described above. In addition, the rear connecting means 15 and the front connecting means 16 are configured to have compression coil springs 72 attached thereto, and therefore have excellent recovery performance from a bent state in which the center line 61C of one transmission shaft 61 and the center line 62C of the other transmission shaft 62 intersect.

[0027] As shown in FIG. 3, a water injection head 50 is provided at the front end of the front transmission shaft 13, to which the rear end of the steel pipe expansion friction type lock bolt 2 is attached. Further, a connecting portion 18 such as a threaded portion for connecting with the tip of the shank rod 30 of the rock drill 3 is provided at the rear end portion of the rear transmission shaft 11 . In other words, the water injection sleeve 26, which is the rear end of the rock bolt 2, is attached to and connected within the water injection head 50, the rear end of the front transmission shaft 13 and the front end of the intermediate transmission shaft 12 are connected by a front connecting means 16 having a sliding mechanism 6 and a limiting mechanism 7, the rear end of the intermediate transmission shaft 12 and the front end of the rear transmission shaft 11 are connected by a rear connecting means 15 having a sliding mechanism 6 and a limiting mechanism 7, and a connecting portion 18 such as a threaded portion formed at the rear end of the rear transmission shaft 11 is connected to a connecting portion not shown in the figure such as a threaded portion formed at the tip of the shank rod 30 of the rock drill 3 via a connecting means not shown, so that force (pressing force, rotational force, etc.) from the rock drill 3 is transmitted to the rock bolt 2 via the force transmission device 1. Therefore, according to the force transmission device 1 of embodiment 1, since it is equipped with a sliding mechanism 6, the force from the rock drill 3 is more easily transmitted to the rock bolt 2, thereby improving the work efficiency of inserting the rock bolt 2 into the hole H. Furthermore, according to the force transmission device 1 of embodiment 1, even when the limiting mechanism 7 functions and the plate portion 65 of one transmission shaft 61 comes into contact with the plate portion 66 of the other transmission shaft 62, the force from the rock drill 3 is transmitted to the rock bolt 2. Therefore, even if the center line of the shank rod 30 of the rock drill 3 and the center line of the rock bolt 2 are not positioned on the same straight line, the force from the rock drill 3 is more easily transmitted to the rock bolt 2, thereby improving the work efficiency of inserting the rock bolt 2 into the hole H.

[0028] As shown in Figure 6, the swivel 40 is equipped with a water intake 41 (see Figure 3(a)) to which a flexible water supply hose 39 (see Figure 1) for supplying water into the steel pipe section 20 of the rock bolt 2 is connected, and is attached to the intermediate transmission shaft 12 so as not to rotate even when the shafts of the force transmission device 1 (rear transmission shaft 11, intermediate transmission shaft 12, front transmission shaft 13) rotate, and is a tubular member for supplying water supplied through the water intake 41 to a water channel formed in the shaft of the force transmission device 1. Water supplied to the swivel 40 via a water supply hose 39 connected to a water supply means such as a pump (not shown) and a water intake 41 formed on the intermediate transmission shaft 12 is supplied to the water injection head 50 via a water passage (not shown) formed on the inside of the swivel 40, an annular groove 42 formed around the outer surface of the intermediate transmission shaft 12, a water inlet 43 formed at the bottom of the annular groove 42, a water passage (not shown) connected to the water inlet 43 and provided on the inside of the intermediate transmission shaft 12, and a water passage pipe 45 connecting a water outlet 44 of the water passage to a water inlet 46 of the water injection head 50. As shown in FIG. 6, the intermediate transmission shaft 12 is configured to be separable into, for example, a swivel mounting shaft 12A having a through shaft portion 12s at its rear end that penetrates the cylindrical inside of the swivel 40, and a connecting shaft 12B to which the swivel mounting shaft 12A is detachably connected. For example, the male threaded portion 12a provided at the rear end of the swivel mounting shaft 12A and the female threaded portion 12b provided at the front end of the connecting shaft 12B are screwed together, thereby allowing the swivel mounting shaft 12A and the connecting shaft 12B to be detachably connected. In other words, the swivel 40 is mounted around the axis of the through shaft portion 12s between the flange portion 12x provided on the swivel mounting shaft 12A and the flange portion 12y provided at the front end of the connecting shaft 12B so as not to rotate together with the through shaft portion 12s. That is, the force transmission device 1 of embodiment 1 is configured with a swivel 40 that is attached to the through shaft portion 12s as the transmission shaft so as not to rotate together with the through shaft portion 12s, and that supplies water taken in from the water intake 41 to the water injection head 50 through a water passage provided in the transmission shaft (intermediate transmission shaft 12, front transmission shaft 13).

[0029] The water injection head 50 is configured as a cylindrical body with an open front end for inserting the water injection sleeve 26 of the lock bolt 2. An annular groove (not shown) corresponding to the annular groove 27 formed in the rear end sealing portion 22 of the lock bolt 2 is formed on the inner peripheral surface of the cylindrical body of the water injection head 50, and watertightness maintaining members such as annular gaskets (not shown) are provided in front and behind the annular groove to maintain watertightness with the outer peripheral surface of the water injection sleeve 26. Furthermore, a stopper (not shown) that comes into contact with the rear end surface 26e of the water injection sleeve 26 of the lock bolt 2 (see FIG. 2(a)) is provided at the rear end of the inner side of the cylindrical body of the water injection head 50. When the water injection sleeve 26 of the lock bolt 2 is inserted into the water injection head 50 and the rear end surface 26e of the water injection sleeve 26 is in contact with the stopper inside the water injection head 50, the front end side of the water injection sleeve 26 protrudes slightly forward beyond the front end surface 51 of the water injection head 50, as shown in Figure 3.

[0030] Therefore, water from a water supply means such as a water injection pump (not shown) is supplied into the steel pipe portion 20 of the rock bolt 2 via the water supply hose 39, swivel 40, intermediate transmission shaft 12 (swivel mounting shaft 12A), water channel pipe 45, water injection head 50, annular groove 27 of the rock bolt 2, and water injection port 28, causing the steel pipe portion 20 to expand and deform from a deformed steel pipe shape to a circular steel pipe shape due to water pressure and become fixed to the inner wall of the hole H.

[0031] In addition, in the case of a steel pipe expansion friction type rock bolt 2, a washer 9 for supporting the wall surface W of the tunnel cavity T is provided at the rear end of the rock bolt 2 that is inserted into the hole H and fixed.

[0032] In the first embodiment, as shown in FIG. 1(b), washer holding means 8 is provided on the tip side of guide 34, and washer 9 described above is releasably held by said washer holding means 8. As shown in FIGS. 7 to 9, the washer holding means 8 is configured to include a washer holding frame 80 and an attachment portion 81 for the guide .

[0033] The washer holding frame 80 includes a frame plate portion 82 and a rear plate portion 83 . The frame plate portion 82 is formed by a frame-shaped plate having an opening cut out at the center of the upper frame portion of a rectangular frame body whose center line extends in the front-rear direction, for example. The rear plate portion 83 extends from the rear edge of the frame plate portion 82 toward the inside of the frame of the frame plate portion 82, and is formed by a plate having a central through-hole 84 with a circular shape and an opening at the top formed in the center. The inner surface of the frame of the frame plate portion 82 and the front plate surface of the rear plate portion 83 are formed on planes that intersect at right angles to each other. The washer 9 is removably held in a recess 85 formed by the inner surface of the frame of the frame plate portion 82 and the front plate surface of the rear plate portion 83 . For example, magnets 86 are attached to positions near the four corners of the front plate surface of rear plate portion 83, which forms the bottom surface of recessed portion 85. The inner diameter of the frame of the frame plate portion 82 is formed to be slightly larger than the outer diameter of the washer 9, for example, a rectangular plate. The washer 9 is stored in the recess 85 with the rear plate surface 91 of the washer 9 facing the front plate surface of the rear plate portion 83 that forms the bottom surface of the recess 85, and the rear plate surface 91 of the washer 9 is attracted to the magnets 86, 86..., thereby removably holding the washer 9 within the recess 85. The washer holding means 8 is fixed to the guide 34 by fixing the mounting portion 81 to the guide 34 with fixing means 87 such as bolts.

[0034] Therefore, with the rock bolt 2 passed through the central through hole 90 of the washer 9 held in the recess 85 of the washer holding means 8 (see Figure 1(b)), the rock bolt 2 is moved to the casting position on the wall surface W, and then when it is inserted into the hole H, the washer 9 held by the washer holding means 8 functions as a means (centralizer) to prevent the rock bolt 2 from shifting axis, making it easier to insert the rock bolt 2 into the hole H.

[0035] Next, the method for installing rock bolts will be explained. First, as shown in FIG. 1(a), a hole H is drilled at a predetermined position on the wall surface W of the tunnel cavity T using a drilling device 4 attached to a boom 31, into which a rock bolt 2 is to be inserted. Next, the force transmission device 1 is attached to the rock drill 3 mounted on the boom 32, and a washer holding means 8 is attached to the tip side of the guide 34 to form the rock bolt mounting device 5, and the rock bolt 2 is attached to the water injection head 50 at the front end side of the force transmission device 1 in the rock bolt mounting device 5. The washer 9 is also set to be held in the recess 85 of the washer holding means 8. Then, by operating the carriage 35 to move the rock drill 3, the rock bolt 2 is passed from the tip side through the central through-hole 90 of the washer 9, as shown in Figure 1(b). Next, the boom 32 and carriage 35 are operated to move the rock bolt 2 in a direction approaching the hole H, and the tip of the rock bolt 2 is positioned at the entrance of the hole H. After that, the boom 32 is operated to bring the front plate surface 92 of the washer 9 held by the washer holding means 8 close to the wall surface W. After that, the carriage 35 is operated to move the rock drill 3 forward while advancing the rock bolt 2, thereby inserting the rock bolt 2 into the hole H (see Figures 1(c) and 1(d)). That is, as shown in Figure 1(d), when the front plate surface 92 of the washer 9 comes into contact with the wall surface W and it becomes impossible to move the rock drill 3 forward, the insertion of the rock bolt 2 into the hole H is completed.

[0036] Once the insertion of the rock bolt 2 into the hole H is complete, water begins to be poured into the steel pipe portion 20 of the rock bolt 2. For example, when the water pressure inside the steel pipe portion 20 of the rock bolt 2 reaches a predetermined construction water pressure, the water injection pump (not shown) serving as a water supply means is stopped, thereby completing the water injection work into the steel pipe portion 20 of the rock bolt 2. When the water injection work is completed, the steel pipe section 20 between the front end sealing section 21 and the rear end sealing section 22 expands and deforms from the state shown by the solid line in Figure 2(a) to the state shown by the imaginary line (double-dashed line), and the outer surface of the expanded steel pipe section 20 between the front end sealing section 21 and the rear end sealing section 22 becomes fixed to the hole wall W within the hole H.

[0037] The diameter of the central through-hole 90 of the washer 9 is formed to correspond to the outer diameter of the small diameter sleeve 25 of the lock bolt 2. Therefore, when the insertion of the lock bolt 2 into the hole H is complete, the inner surface of the central through hole 90 of the washer 9 and the outer surface of the small diameter sleeve 25 are in close proximity, the washer 9 is positioned on the outer surface of the small diameter sleeve 25, and the rear plate surface 91 of the washer 9 and the front end surface 29 of the water injection sleeve 26 (the step surface that forms the boundary between the outer surface of the small diameter sleeve 25 and the outer surface of the water injection sleeve 26 (see Figure 2(a))) are in close proximity. Thereafter, as shown in FIG. 1(e), the boom 32 is operated to move the lock bolt setting device 5 in a direction away from the hole H. This causes the water injection head 50 of the force transmission device 1 to detach from the water injection sleeve 26. Furthermore, when the washer holding means 8 moves in a direction away from the hole H, the washer 9 detaches from the magnets 86, 86... of the washer holding means 8 and is caught on the front end surface 29 of the water injection sleeve 26, so that the washer 9 is attached to the rear end of the rock bolt 2, supporting the wall surface W of the tunnel cavity T and preventing the rock bolt 2 from slipping out of the hole H.

[0038] According to the force transmission device 1 of embodiment 1, which is installed between the rock drill 3 and the rock bolt 2 and transmits the force from the rock drill 3 to the rock bolt 2, it is equipped with a rear connecting means 15 having a sliding mechanism 6 and a limiting mechanism 7, and a front connecting means 16, so that it is possible to prevent excessive force from being applied to the rock bolt 2 and to enable the rock bolt to be inserted straight into the hole H. In particular, in the case of a steel pipe expansion type friction type rock bolt 2, if the steel pipe section 20 is bent, it may become impossible to reliably inject water into the steel pipe section 20, and the rock bolt 2 may not be able to be fixed to the wall of the hole H. Therefore, being able to insert the steel pipe expansion type friction type rock bolt 2 straight into the hole H has the excellent effect of enabling the installation work of the steel pipe expansion type friction type rock bolt 2 to be carried out accurately and reliably.

[0039] Furthermore, since the rear connecting means 15 and the front connecting means 16 are equipped with a sliding mechanism 6 and a limiting mechanism 7, even if the center line of the shank rod 30 of the rock drill 3 and the center line of the rock bolt 2 are not positioned on the same straight line, the force from the rock drill 3 is easily transmitted to the rock bolt 2, making it possible to efficiently insert the rock bolt straight into the hole H.

[0040] Furthermore, the force transmission device 1 includes a rear transmission shaft 11, an intermediate transmission shaft 12, a front transmission shaft 13, a rear connecting means 15 that connects the front end of the rear transmission shaft 11 to the rear end of the intermediate transmission shaft 12, and a front connecting means 16 that connects the front end of the intermediate transmission shaft 12 to the rear end of the front transmission shaft 13. This increases the degree of freedom in the bending direction of the shafts of the rear transmission shaft 11, the intermediate transmission shaft 12, and the front transmission shaft 13, and makes it possible to more effectively prevent excessive force from being applied to the lock bolt 2.

[0041] Furthermore, because the force transmission device 1 includes the swivel 40, when the shafts (rear transmission shaft 11, intermediate transmission shaft 12, front transmission shaft 13) of the force transmission device 1 are rotated, it is possible to prevent the water supply hose 39 connected to the water intake 41 of the swivel 40 from becoming tangled around the shaft. In other words, even when the shaft of the force transmission device 1 is rotated, the water supply hose 39 connected to the water intake 41 can be prevented from becoming tangled around the shaft.

[0042] Furthermore, the rock bolt mounting device 5 is configured to include a rock drill 3, a force transmission device 1 of embodiment 1 connected to the tip side of the shank rod 30 of the rock drill 3, and a washer holding means 8.Therefore, by passing the rock bolt 2 through the central through hole 90 of the washer 9 held in the recess 85 of the washer holding means 8, the washer 9 held by the washer holding means 8 can function as a means for preventing axial misalignment of the rock bolt 2, making it easier to insert the rock bolt 2 into the hole H.

[0043] Embodiment 2 In the first embodiment, a force transmission device 1 is exemplified that includes a rear transmission shaft 11, an intermediate transmission shaft 12, a front transmission shaft 13, a rear connecting means 15 that connects the front end of the rear transmission shaft 11 to the rear end of the intermediate transmission shaft 12, and a front connecting means 16 that connects the front end of the intermediate transmission shaft 12 to the rear end of the front transmission shaft 13, but a force transmission device that includes only one connecting means may also be used. In other words, when driving a rock bolt from a tunnel cavity into the natural ground, a force transmission device that is provided between the rock drill and the rock bolt to transmit the force from the rock drill to the rock bolt comprises a rear transmission shaft whose rear end is attached to a pressing means, a front transmission shaft whose front end has the rock bolt attached to it, and a connecting means that connects the front end of the rear transmission shaft to the rear end of the front transmission shaft, and the connecting means may be configured to comprise a sliding mechanism between the front end of the rear transmission shaft and the rear end of the front transmission shaft that operates to allow the center lines of the rear transmission shaft and the front transmission shaft to intersect, and a limiting mechanism that limits the sliding range of the sliding mechanism so that the intersection angle between the center line of the rear transmission shaft and the center line of the front transmission shaft does not exceed a predetermined angle. That is, the force transmission device may be configured to include a rear transmission shaft, a front transmission shaft, and a connecting means.

[0044] Although the washer 9 is a square plate having a square surface, the washer may be formed of, for example, a circular plate having a circular surface. In this case, the washer holding means may have a recess that can accommodate the washer formed of a circular plate, and a magnet on the bottom surface of the recess for attracting and holding the washer.

[0045] Although the above example illustrates a steel pipe expansion friction type rock bolt 2 that expands and deforms using water pressure, an expansion friction type rock bolt that expands and deforms using air pressure may also be used. That is, the rock bolt may be an expansion friction type rock bolt that expands and deforms using fluid pressure such as water or air.

[0046] In addition, the above example shows the insertion of a steel pipe expansion friction type rock bolt 2 into a hole H using a force transmission device 1, a rock bolt installation device 5 equipped with the force transmission device 1 and a washer holding means 8, but the force transmission device 1 of the present invention, a rock bolt installation device 5 equipped with the force transmission device 1 and a washer holding means 8 can also be used when inserting into a hole H a fixing material type rock bolt that is fixed to the hole wall of the hole H via a fixing material such as a mortar-based or resin-based material. In the case of an anchoring type lock bolt, a nut can be screwed onto the threaded portion formed on the rear end of the lock bolt in advance, and after the lock bolt has been fixed into the hole H, the nut can be further tightened to fix the washer 9 to the wall surface W.

[0047] In addition, although the above example shows the use of a rock drill as the pressing means, the pressing means may be a machine other than a rock drill. In other words, in the present invention, the pressing means may be any means that applies a pressing force to the rock bolt via a force transmission device. [Explanation of symbols]

[0048] 1 Force transmission device, 2 Rock bolt, 3 Rock drill (pressing means), 6 Sliding mechanism, 7 limiting mechanism, 11 rear transmission shaft, 12 intermediate transmission shaft, 13 front transmission shaft, 15 rear connecting means, 16 front connecting means, 40 swivel, 41 water intake, 50 water injection head, 63 spherical, 64 spherical seat.

Claims

1. A force transmission device that is provided between a pressing means and a rock bolt to transmit force from the pressing means to the rock bolt when the rock bolt is driven into the natural ground from a tunnel cavity, The transmission device includes a rear transmission shaft having a rear end attached to the pressing means, a front transmission shaft having a lock bolt attached to its front end, an intermediate transmission shaft provided between the rear transmission shaft and the front transmission shaft, a rear connecting means that connects the front end of the rear transmission shaft to the rear end of the intermediate transmission shaft, and a front connecting means that connects the front end of the intermediate transmission shaft to the rear end of the front transmission shaft, The rear connecting means is a sliding mechanism between the front end of the rear transmission shaft and the rear end of the intermediate transmission shaft that operates to allow a state in which the center line of the rear transmission shaft and the center line of the intermediate transmission shaft intersect; a limiting mechanism for limiting the sliding movement range of the sliding mechanism so that the intersection angle between the center line of the rear transmission shaft and the center line of the intermediate transmission shaft does not exceed a predetermined angle; The front connecting means is a sliding mechanism for the front end portion of the intermediate transmission shaft and the rear end portion of the front transmission shaft that operates to allow a state in which the center line of the intermediate transmission shaft and the center line of the front transmission shaft intersect; a limiting mechanism for limiting the sliding movement range of the sliding mechanism so that the intersection angle between the center line of the intermediate transmission shaft and the center line of the front transmission shaft does not exceed a predetermined angle; the sliding mechanism is constituted by a spherical sliding mechanism in which a spherical surface provided at one end of one transmission shaft slides on a spherical seat provided at one end of the other transmission shaft; the spherical surface is configured as a hemispherical spherical surface formed so as to protrude from a plate surface of a plate portion provided at one end of one of the transmission shafts, and the plate surface of the plate portion is positioned on a plane perpendicular to the center line of the one of the transmission shafts; The spherical seat is formed so as to be recessed from the plate surface of a plate portion provided at one end of the other transmission shaft, and is configured with a hemispherical concave surface that is in full contact with the spherical surface, and the plate surface of the plate portion is positioned on a plane perpendicular to the center line of the other transmission shaft, The limiting mechanism is configured such that, when the center line of one transmission shaft is aligned with the center line of the other transmission shaft and the spherical surface is in contact with the spherical seat, the plate surface of the plate portion of one transmission shaft and the plate surface of the plate portion of the other transmission shaft are parallel and face each other at a predetermined distance, and when the intersection angle between the center line of one transmission shaft and the center line of the other transmission shaft reaches a predetermined angle, the peripheral edge of the plate surface of one plate portion comes into contact with the plate surface of the other plate portion, thereby limiting the intersection angle so that it does not exceed the predetermined angle.

2. A force transmission device that is provided between a pressing means and a rock bolt to transmit force from the pressing means to the rock bolt when the rock bolt is driven into the natural ground from a tunnel cavity, a rear transmission shaft having a rear end attached to the pressing means, a front transmission shaft having a lock bolt attached to its front end, and connecting means for connecting the front end of the rear transmission shaft and the rear end of the front transmission shaft, The connecting means is a sliding mechanism between the front end portion of the rear transmission shaft and the rear end portion of the front transmission shaft that operates to allow a state in which the center lines of the rear transmission shaft and the front transmission shaft intersect; a limiting mechanism that limits the sliding movement range of the sliding mechanism so that the intersection angle between the center line of the rear transmission shaft and the center line of the front transmission shaft does not exceed a predetermined angle; the sliding mechanism is constituted by a spherical sliding mechanism in which a spherical surface provided at one end of one transmission shaft slides on a spherical seat provided at one end of the other transmission shaft; the spherical surface is configured as a hemispherical spherical surface formed so as to protrude from a plate surface of a plate portion provided at one end of one of the transmission shafts, and the plate surface of the plate portion is positioned on a plane perpendicular to the center line of the one of the transmission shafts; The spherical seat is formed so as to be recessed from the plate surface of a plate portion provided at one end of the other transmission shaft, and is configured with a hemispherical concave surface that is in full contact with the spherical surface, and the plate surface of the plate portion is positioned on a plane perpendicular to the center line of the other transmission shaft, The limiting mechanism is configured such that, when the center line of one transmission shaft is aligned with the center line of the other transmission shaft and the spherical surface is in contact with the spherical seat, the plate surface of the plate portion of one transmission shaft and the plate surface of the plate portion of the other transmission shaft are parallel and face each other at a predetermined distance, and when the intersection angle between the center line of one transmission shaft and the center line of the other transmission shaft reaches a predetermined angle, the peripheral edge of the plate surface of one plate portion comes into contact with the plate surface of the other plate portion, thereby limiting the intersection angle so that it does not exceed the predetermined angle.

3. A force transmission device as described in claim 1 or claim 2, characterized in that each connecting means is configured such that a bolt through hole that passes through one of the plate portions is formed on the peripheral side of the plate surface of one of the plate portions, and a bolt through hole that passes through the other plate portion is formed on the peripheral side of the plate surface of the other plate portion, and the shank of a bolt that passes through the bolt through hole of one plate portion and the bolt through hole of the other plate portion passes through the hollow portion of the compression coil spring, and a nut is fastened from the tip side of the shank of the bolt, so that the compression coil spring is attached between the other plate portion and the nut.

4. 4. A force transmission device according to claim 1, wherein the front end of the front transmission shaft is provided with a water injection head to which the rear end of a steel pipe expansion type friction lock bolt is attached.

5. 5. The force transmission device according to claim 4, further comprising a swivel having a water intake port, attached to the transmission shaft so as not to rotate together with the transmission shaft, and supplying water taken in from the water intake port to the water injection head through a water passage provided in the transmission shaft.

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