KR100494187B1 - Belt-shaped grinding tool - Google Patents

Abstract

The present invention relates to a belt-type grinding tool that can perform the rotation direction of the grinding belt, the driving and stopping of the grinding belt with one air valve,

An endless grinding belt is installed tightly between the driven pulley attached to the tip of the tension bar freely attached to the housing and the drive pulley attached to the air motor attached to the housing, and the grinding belt is rotated by the air motor. It is a belt-type grinding tool that can be installed, the valve of the belt-type grinding tool to the air motor supply and exhaust to the air motor is installed, the air motor can be rotated or stopped by advancing or retracting the valve, In addition, it is characterized in that the rotation operation to the right or left in the state in which the valve is advanced to stop or reverse the rotation of the air motor.

Description

Belt Grinding Tools {BELT-SHAPED GRINDING TOOL}

The present invention relates to a belt type grinding tool having an endless grinding belt which is tensioned by a pair of driven pulleys and a driving pulley, and in particular, one valve is operated to rotate the grinding belt, to drive and stop the grinding belt. The present invention relates to a belt-type grinding tool that can be simply switched and that the grinding work can be performed without any irrationality in either right- or left-handed workers.

Referring to Fig. 9, a configuration of a conventionally known belt-type grinding tool will be described. In the drawing, “101” is a grip, “102” is a gripper and an integral prime mover (air motor), and “103” is a driving roller (driving). Pulley), “104” is an arm with a built-in spring, “105” is a tension rod (tension bar) pressurized to the spring, and “106” is a support arm of a driven roller (driven pulley) 107 attached to the rod. "108" is a grinding belt clamped tightly between a driving roller and a driven roller, "109" is a shoe, and "110" is a belt cover. In the belt-type grinding tool having the above configuration, the grip is held by the right hand, the prime mover 102 is driven to rotate the grinding belt 108, and the belt is placed on the surface of the workpiece (not shown) to grind the surface of the workpiece. do.

However, the belt-type grinding tool as described above usually sets the positional relationship between the grip and the grinding belt in accordance with the right-handed worker, so that the use of the grinding tool by the left-handed worker becomes unnatural. That is, the left-handed worker performs the grinding work by holding the grip with the left hand of the well-used side, and thus the belt position becomes more left than the left hand, so it is very difficult to perform the grinding work. In addition, if the grip of the belt-type grinding tool is rotated 180 degrees (in the state of the drawing, the grip is directly in front of the drawing belt and the grinding belt is on the top of the drawing), the grinding belt and the grip are attached when the grip is carried out with the left hand. It is difficult to work because the posture becomes unnatural when the grinding belt is placed on the grinding part at an angle or positional relationship. Moreover, in the conventional belt type grinding tool, since the rotational direction of the grinding belt is constant, the operator cannot select the desired rotational direction, which is poor in usability. In addition, when the grinding belt is replaced due to breakage or wear of the grinding belt, the belt grinding tool needs to push the tension rod against the elastic support force of the spring by hand, thus making it difficult to replace the belt. .

Therefore, the present invention can freely select the rotation direction of the grinding belt by simply operating one valve, and can stop the rotation of the air motor at any position, and can also fix the tension bar when replacing the grinding belt. An object of the present invention is to provide a belt-type grinding tool employing a lock mechanism and to solve the problems of the conventional belt-type grinding tool. In addition, an object of the present invention is to provide a belt grinding tool that can easily change the position of the offset bracket having a tension pulley according to the use state of the belt.

According to the present invention, the air flow can be changed by moving one valve forward to further rotate the electrostatic or reverse rotation direction of the grinding belt, and the air flow simply by retracting the valve. It is designed to stop the rotation of the grinding belt by blocking the. For this reason, in this belt grinding tool, even if the direction of the grinding tool itself is set to the left-handed or the right-handed, the rotational direction of the grinding belt can be freely selected, which is very useful. Therefore, even a left-handed worker can work in the same sense of use as a right-handed worker. When the grinding belt needs to be replaced, the tension bar can be fixed simply by pushing in the tension bar and locking the state so that the grinding belt can be easily replaced.

Technical solution employed by the present invention to achieve the above object,

An endless grinding belt can be tightly installed on the driven pulley attached to the tip of the tension bar freely attached to the housing and the drive pulley attached to the air motor attached to the housing, and the grinding belt can be rotated by the air motor. It is a belt-type grinding tool, and the valve of the belt-type grinding tool is provided for the supply and exhaust of the air motor, the air motor can be rotated or stopped by advancing or retracting the valve, It is a belt type grinding tool, characterized in that the rotation operation to the right or left in the state in which the valve is advanced to electrostatically or reverse the rotation of the air motor.

The valve is composed of a valve body formed with an air supply passage and an air exhaust passage of the air, and a valve ring freely rotatable and slidably attached to the valve body, and formed on the valve body side on the inner circumferential surface of the valve ring. An annular groove for communicating the air supply passage to the air source, a sealing ring for blocking the air source on both sides of the annular groove, and a projection for sliding freely fitting in the guide groove formed in the axial direction of the valve body, The air supply passage communicates with the air source through the annular groove by advancing the ring along the guide groove of the valve body, and in this state, the valve body also interlocks through the projection by rotating the valve ring to the right or left side. And the air supply passage formed in the valve body communicates with the air supply / exhaust hole of the air motor attached in the housing. A belt-type grinding tool, characterized in that to a power failure or inversion.

An end of the valve ring is provided with a stopper made of an elastic body, and an inclined surface protruding inward is formed on an inner circumferential surface of the opposite housing, and a pass portion through which the stopper can pass is provided on the inclined surface. It is possible to advance the valve ring only when the stopper is in a position opposite to the passage, and the valve ring allows the stopper to retract the valve ring over the inclined surface at any position. Grinding tool.

The inner peripheral surface of the end portion of the housing is a belt type grinding tool, characterized in that a ring member having the passage portion and the inclined surface is attached.

The tension bar is a belt type grinding tool, characterized in that it is provided with a lock mechanism that can lock the tension bar in a state in which the tension bar is pushed in.

In addition, an offset bracket having a tension pulley near the drive pulley of the housing is a belt type grinding tool, which can be detachably attached to the housing by changing its position.

EMBODIMENT OF THE INVENTION Hereinafter, embodiment which concerns on this invention is described with reference to drawings, FIG. 1 is a top view of the belt type grinding tool which concerns on this embodiment, FIG. 2 is the same side view, FIG. 3 is AA sectional drawing of FIG. 2, FIG. (A) to (c) are explanatory views of the structure and operation of the lock mechanism of the tension bar, FIG. 5 is an enlarged cross-sectional view of the air motor portion, and FIG. 6 (a) and (b) are the valve rings and the valve body constituting the valve. Fig. 7 is a view of the valve body, (a) is a plan view, (b) and (c) is a cross-sectional view, (d) is a side view, and Figs. It is explanatory drawing and is an exploded view which shows the state of the air supply and exhaust by the cross section of a cylinder and a valve main body.

The belt-type grinding tool (hereinafter referred to as grinding tool) according to the present invention is a tension mechanism (T) for holding a grinding belt, a grinding belt (B) tightly installed on a driving pulley and a driven pulley, and providing a rotational force to the grinding belt. Grip (G) with built-in air motor (A), valve (V) for supplying air to the air motor (A) and exhausting from the air motor (A), and the like (G) By operating the valve (V) attached to the valve, the rotation of the air motor (A) can be reversed or reversed, and the grinding belt can be selected to rotate in the forward or forward direction of the operator to grind the surface of the workpiece. It is. Hereinafter, the configuration will be described in detail by dividing each component.

[Tension mechanism]

2 and 3, "1" is a tension bar, and a pulley holding member 3 for rotatably holding the driven pulley 2 is attached to the tip thereof. The pulley holding member 3 is freely attached to the front end of the tension bar 1 in the up and down direction (arrow) in FIG. 3 by the shaft 4, and the screw 5 for adjusting the swing angle is adjusted. The screw 6 and the spring 7 are provided between them. With this configuration, the angle of the pulley holding member 3 is adjusted with the shaft 4 as the point by twisting or loosening the adjusting screw 6 against the elastic bearing force of the spring 7 in FIG. The grinding belt B can thus be positioned on the center of the tension bar 1. At this time, the pulley holding member 3 is fixed at an adjusted angle with the screw 5.

The end of the tension bar 1 on the opposite side to the driven pulley 2 is inserted freely in the long hole 8c provided in the housing 8, and the tube member 9 is provided at the distal end of the long hole 8c. It is fixed by the screw 10 with respect to (8). Moreover, the notch part 11 (upper and lower in FIG. 3) is formed in the cylinder member 9 in parallel with the axis center of the tension bar 1, and the pin attached to the tension bar 1 in this notch part 11 ( 12) is inserted, and the pin 12 prevents the tension bar 1 from rotating around the shaft center.

3 and 4, a small diameter portion 13a is formed at one end (right side in the drawing) of the tension bar 1 inserted into the long hole 8c of the housing 8, and this small diameter portion 13a is formed. The circumferential groove 14 is formed in the stepped portion of the large diameter portion 13b, and a plurality of protrusions 15 are formed at the end of the tension bar 1. In addition, a spring support member 16 is disposed at the right end of the tension bar 1, and a tension spring 17 is disposed between the spring support member 16 and the housing 8. In addition, as shown in Fig. 4A, an L-shaped push button 18 is disposed in the housing 8, and a tension bar 1 is disposed through the push button 18. As shown in Figs. The push button 18 is elastically supported downward in the drawing by the spring 19, and when the grinding belt B is in use, the small diameter portion of the tension bar 1 as shown in Fig. 4 (b). It is in the state of contacting 13a.

In the case of replacing the grinding belt B by the above configuration, the tension bar 1 is pushed against the elastic bearing force of the tension spring 17 so that the stepped portion of the small diameter portion 13a and the large diameter portion 13b is moved. When the formed circumferential groove 14 comes to the position of the push button 18, the push button 18 falls into the circumferential groove 14 by the elastic bearing force of the spring 19 (see Fig. 4 (a)), and the tension Replace the grinding belt (B) while locking the movement of the bar (1). In addition, when the grinding belt (B) is cut during operation, the tension bar (1) tries to pop out to the left in the drawing from the state shown in Fig. 4 (B) by the elastic support force of the tension spring (17), the tension bar (1) Since the plurality of protrusions 15 provided at the end of the hook is caught by the push button 18 (see FIG. 4 (C)), the tension bar 1 is prevented from popping out. In addition, the push button 18 is pushed against the elastic bearing force of the spring 19 to return the replaced grinding belt B to the state in which the replaced grinding belt B is tightened (Fig. 4 (b)). The tension bar slides to the left in the drawing from the circumferential groove 14, and returns to the state of FIG.

In Fig. 2, the housing 8 is provided with a space between the grinding belt B and the tension bar 1 to freely rotate the tension pulley 20 for grinding the curved surface of the workpiece (not shown). The supported offset bracket 21 is attached. The offset bracket 21 has a U-shape on the tension pulley 20 side, and can be inserted into the guide grooves 22 of the housing 8 on both sides of the U-shaped plates 21a and 21b. It is extended and can be attached to the housing 8 (in FIG. 2, the offset bracket 21 is fitted to the housing 8 from the lower side to the upper side in the figure). This offset bracket 21 is pulled downward in FIG. 2, removed from the housing 8, and the offset bracket 21 is moved upward from the top of the housing 8 again with the tension pulley 20 upward. (In this case, the left-handed worker reverses the grinding tool 180 degrees.) In addition, the projections 23 and 23 protruding inward are provided on both side plates 21a and 21b of the offset bracket 21, and the fitting recesses (not shown) are formed on the housing 8 side to offset them. Positioning of the offset bracket 21 into the housing 8 and positioning of the offset bracket 21 by fitting the bracket 21 and fitting the protrusion 23 into the recessed portion on the housing 8 side. Falling out of the housing 8 can be prevented. Either of the offset bracket 21 or the housing 8 for mounting the projection 23 or the fitting recess for preventing such fallout can be freely set at design time.

[Air motor]

The air motor has the same configuration as a conventional grinding tool, and when air is supplied, the rotor having the blades in the motor rotates, thereby rotating the grinding belt through the driving pulley.

In FIG. 5, the air motor A includes a rotor 24 having an inner diameter eccentrically attached to the housing 8, a blade 25a rotatably disposed within the cylinder 24, and It is comprised by the plates 24c and 24d which insert the rotor 25 from both sides of the cylinder 24, The shaft 26 of the both ends of the rotor 25 is the bearing 27 provided in the plates 24c and 24d. It is axially supported by. The drive pulley 28 is fixed to the end of one side of the rotor 25 (lower side in the figure) by the nut 29, and the drive pulley 28 and the tension bar 1 described above. An endless grinding belt B is attached to the driven pulley 2 and the tension pulley 20 installed at the tip of the head (see Fig. 1).

The cylinder 24 is provided with holes 24a and 24b (described in detail in the valve mechanism described later) for supplying and exhausting air, and between the outer circumference of the cylinder 24 and the housing 8. A flow path 30 for evacuating is formed. On the wall of the housing 8 on the opposite side, two holes 8a and 8a (see FIG. 8 to be described later) for supplying or exhausting air to the air motor A are connected to the flow path 30. The exhaust holes 31 and 31 are formed, and the valve main body 33 of the valve V mentioned later is arrange | positioned facing these two holes 8a and 8a. In this air motor A, when the valve V is operated, air is supplied to the air motor A, and the rotor 25 is rotated. The air supplied in the cylinder 24 rotates the rotor 25 having the blades 25a, and is exhausted to the outside from the exhaust hole 31 and the hole 8a on the side of the exhaust through the flow path 30. It is. In addition, a cover 32 detachably attached to the outer side of the drive pulley 28 (lower side in FIG. 5) for replacing the grinding belt B or the like is detachably attached by a screw 32A (see FIG. 3). .

[Valve Mechanism]

In FIG. 6, FIG. 7, FIG. 8, the valve V is for supplying and exhausting air to the above-described air motor A, and is composed of a valve body 33 and a valve ring 34, and the valve ring ( 34 is not rotatable relative to the outer circumference of the valve body 33 and is attached freely sliding. With this configuration, when the valve ring 34 is advanced on the valve body 33, air is supplied to the air motor A through the valve body 33, and the valve ring 34 is advanced. When rotated, the valve main body 33 also rotates in association with each other, whereby air can be supplied from the valve main body 33 to the air motor A (detailed configuration will be described later).

The valve main body 33 has the shape shown in FIG. 7, and as shown in FIG. 6, one end of the valve main body 33 is freely rotated about the shaft center by the fixing ring 35 and the ring nut 36. It is fixed to (8). The first air supply passage 37 and the second air supply passage 38 are formed in the central portion of the valve body 33, and the communication holes 39 communicate with the outer circumference of the valve body 33 in each of the air supply passages 37 and 38. , 40) are formed. In addition, the second air supply passage 38 has a seal ring 41 around the outlet, and through the seal ring 41, two holes 8a (see the right-side development diagram in Fig. 8) for supply / exhaust air are also provided. It is in contact with the surface of the housing 8 which has it (refer FIG. 6). In Fig. 6, the upper and lower air supply holes 8a are shown in the upper half of the housing 8, and the exhaust hole 31 is shown in the lower half.

Moreover, the valve body 33 is provided with the pin 42 which regulates the rotation angle of the valve body 33, and this pin 42 is inserted in the recessed part 8b formed in the housing side. For this reason, the valve main body 33 can move in the recessed part 8b from the position of the neutral of FIG. 8 until the pin 42 contacts the left and right walls of the recessed part 8b. Moreover, as shown in FIG. 6, the 1st air supply path 37 is provided with the hose connection part 52 for air supply. 6 and 7, an exhaust passage 43 is formed in the valve body 33, and the exhaust passage 43 is an exhaust passage 53 formed on the outer circumference of the air supply hose connecting portion 52. (Refer FIG. 6), it is possible to discharge air to the outside air through the exhaust hose 54.

On the outer circumference of the valve body 33, the valve ring 34 is not rotatable and is slidably arranged. That is, the guide groove 45 is formed in the outer circumference of the valve body 33 in the axial direction, and the projection 46 formed in the inner circumference of the valve ring 34 fits in the guide groove 45, and both It is configured to be relatively incapable of rotation. Further, an annular groove 47 is formed in the inner circumference of the valve ring 34 to communicate the communication holes 39 and 40 of the valve body 33 with each other. Both sides of the groove 47 are provided with a sealing ring 48 for sealing the outer circumferential surface of the valve body 33 and the inner circumferential surface of the housing 8. The one seal ring 48 is disposed between the communication hole 39 and the communication hole 40 when the valve ring 43 is retracted to stop the air supply to the air motor A.

In addition, at least one stopper 49 made of spring material is fixed to the valve ring 34 so as to elastically start in the inner and outer diameter directions, and the stopper 49 can pass through the housing 8 on the opposite side. The valve stopper ring 50 which has the part 50a, the step part 50b which prevents entry, and the inclined surface 51 is provided. In this example, the passage part 50a notches a part of the valve stopper ring 50, and is comprised. This valve stopper ring 50 has the shape which has the inclined surface 51 which protrudes inward as shown in FIG. For this reason, the valve ring 34 can be advanced from the state of FIG. 6 (a) to the state of FIG. 6 (b) only when the stopper 49 passes through the passage portion 50a provided in the valve stopper ring 50. In addition, the valve ring 34 has a configuration in which the stopper 49 can be deformed and retracted from a position at any rotational angle with respect to the housing 8. When the valve ring is to be advanced at another position, the stopper 49 abuts against the step portion 50b to prevent the valve ring 34 from moving forward. Although the step part 50b is formed in this example, a simple end part may be sufficient.

When the stopper 49 advances the valve ring 34 in a state where it can pass through the passage part 50a provided in the stopper ring 50, one seal ring 48 provided on the inner circumference of the valve ring 34 is provided. Located in front of the passage hole 40, the annular groove 47 is positioned so as to span the communication hole 39 and the communication hole 40 on the valve body 33 side, so that the first air supply passage 37, The second air supply passage 38 communicates with it (see Fig. 6 (b)). When the valve ring 34 is rotated in this state, the valve body 33 rotates until the pin 42 contacts the wall of the recess 8b formed in the housing 8, and is formed on the valve body 33. One second air supply passage 38 communicates with one of the air supply and exhaust holes 8a formed in the housing 8, and the other air supply and exhaust holes 8a are connected to the valve body 33. The air motor A can be rotated in communication with the formed exhaust passage 43 (see FIG. 8). At the time of rotation of the air motor A, the exhaust from the air motor A is exhausted from the flow path 30 (see FIG. 5) formed between the cylinder 24 and the housing 8 and the housing 8. The air is discharged through the exhaust hose 54 through the exhaust passage 43 formed in the dragon hole 31 and the valve body 33. When the valve ring 34 is retracted during the rotation of the air motor A, the stopper 49 elastically deforms and moves over the inclined surface 51 of the valve spring 50. As a result, one of the seal rings 48 provided on the inner circumference of the valve ring 34 is positioned between the communication hole 39 and the communication hole 40 so that the first air supply passage 37 and the second air supply passage 38 are located. ) Communication is interrupted and the rotation of the air motor can be stopped.

As shown in FIG. 8, the cylinder 24 having an internal diameter eccentrically disposed to face the valve V having the above-described configuration includes a rotor 25 having a blade 25a therein. Two holes 24a and an exhaust hole 24b are formed. The housing 8 arranged on the outer periphery of the cylinder 24 is formed with the above-mentioned hole 8a corresponding to the hole 24a for supply / exhaust of the cylinder 24, and the housing 8 has a sealing ring ( Through 41), a valve body 33 having the above-described configuration is disposed (see FIGS. 5 and 6). For this reason, when the valve body 34 is advanced and the valve body 33 is rotated through the valve ring 34 in this state, one side hole 8a formed in the second air supply passage 38 and the housing 8 is formed. ) And air are supplied into the cylinder 24 through the hole 24a of one side formed in the cylinder 24, and the rotor 25 can be rotated through the blade 25a (refer FIG. 8). At this time, one of the air exhausted from the air motor A enters the passage 30 formed between the cylinder 24 and the housing 8 from the hole 24b for exhausting the cylinder 24, and exhausts the air. The exhaust passage 43 provided in the valve body 33 is passed through the hole 31 for the dragon, and the other side is the other hole 8a for the supply / exhaust from the other hole 24a for the exhaust. The exhaust passage 43 is reached through the air passage, and both air is discharged to the outside air through the exhaust hose 54.

The operation of the grinding tool having the above configuration will be described.

In FIG. 3, when the valve ring 34 is rotated and the stopper 49 provided on the valve ring 34 is advanced in accordance with the passage portion 50a of the valve stopper ring 50 provided on the housing 8, the valve One side of the seal ring 48 provided at the inner circumference of the ring 34 is located in front of the communication hole 40, and the groove 47 is interposed between the communication hole 39 and the communication hole 40 so as to be the first. The air supply passage 37 and the second air supply passage 38 communicate with each other. At this time, the air is in a state of neutral (Fig. 8 (b)) in which air is not supplied to the air motor (A). When the valve ring 34 is rotated in this state, the valve main body 33 also rotates in conjunction with each other, and the pin 42 provided at the tip of the valve main body 33 of the concave portion 8b formed in the housing 8. When it moves to reach a wall (FIG. 8 (a)), the 2nd air supply path 38 will communicate with the hole 8a of the one side for air supply and exhaust which the housing 8 formed, and the air motor A will be opened. It rotates, the grinding belt B rotates by rotation of the air motor A, and grinding operation can be performed. In addition, when the valve ring 34 is rotated in the opposite direction from the above in the state in which the valve ring 34 is advanced, the valve body 33 also rotates in the reverse direction so that the pin 42 provided in the valve body 33 is The air supply and exhaust that the second air supply passage 38 is formed in the housing 8 while rotating until reaching the wall of the recess 8b on the opposite side formed on the housing 8 side (Fig. 8 (C)). The air motor A can be rotated in the opposite direction from the above by communicating with the hole 8a on the side opposite to the dragon hole 8a, and the air belt A can be reversed to reversely rotate the grinding belt B. .

To finish the grinding operation, when the valve ring 34 is retracted in the state as it is, the stopper 49 deforms to exceed the inclined surface 51 of the valve stopper ring 50, and the groove formed in the inner circumference of the valve ring 34. One of the sealing rings 48 fitted with the 47 is positioned between the communication hole 39 and the communication hole 40 to block the air to stop the rotation of the air motor A. FIG.

When replacing the grinding belt (B), the rotation of the air motor (A) is stopped, the mounting screw (32A) is removed to remove the cover (32), and the tension bar (1) of the tension spring (17). When the circumferential groove 14 formed in the tension bar 1 comes to the position of the push button 18 when pushed against the elastic support force, the push button 18 is circumferential groove (the elastic support force of the spring 19). 14), in other words, the push button 18 is pushed outward by the elastic bearing force of the spring 19 (see Fig. 4 (a)) to lock the movement of the tension bar 1, grinding in this state The belt B can be replaced.

In addition, when the grinding belt B is cut during operation, the tension bar 1 protrudes to the left in the drawing due to the elastic support force of the tension spring 17. The projection 15 provided at the end of the tension bar 1 is provided. Touches one end of the pushbutton 18, it is possible to prevent the tension bar 1 from protruding from the housing 8.

When the left-handed worker uses the air grinding tool in the normal state (the grinding belt B rotates counterclockwise), the offset bracket 21 attached to the lower side of the housing 8 is changed upward. Then, the grinding tool is inverted by 180 degrees to advance the valve ring 34 and also rotate the valve ring 34 in the reverse direction. According to the working situation, the direction of grinding of the grinding powder can be reversed by forward and reverse rotation of the valve body 33 through the valve ring 34 to switch the rotation direction of the grinding belt B. In addition, when the work is finished or stopped, the rotation of the air motor A can be stopped simply by retracting the valve ring 34 as described above. When the offset bracket 21 is attached, curved grinding can be performed, and plane grinding can be performed by removing the offset bracket.

As mentioned above, although embodiment which concerns on this invention was described, the passage of the air formed in the valve ring, the valve body, and the housing | casing can be made into various passage shapes as long as the passage which can achieve the above-mentioned function. As the means for fixing the offset bracket, various forms such as screws can be adopted. In addition, the said embodiment is only an illustration and this invention can be implemented in other various forms, without deviating from the mind or main characteristic of this invention, It should not interpret it limitedly.

As described in detail above, according to the present invention, the grinding belt can be rotated and stopped only by operating one valve, and the rotational direction of the grinding belt can be freely selected. Grinding can be done with a sense. In addition, by changing the rotational direction of the grinding belt, the scattering direction of the grinding powder can be selected, thereby improving work efficiency. In addition, when the belt is replaced, the locking mechanism that can easily fix the tension bar is adopted, thereby making it easy to replace the grinding belt. In addition, since the offset bracket having the tension pulley can be attached and detached freely, excellent effects such as being easy to grind even a curved surface can be achieved.

BRIEF DESCRIPTION OF THE DRAWINGS The top view of the belt type grinding tool which concerns on this embodiment.

2 is a side view of the same;

3 is a cross-sectional view of the same plane.

4A to 4C are explanatory diagrams of the configuration and operation of the lock mechanism.

5 is an enlarged cross-sectional view of the air motor portion.

6 (a) and 6 (b) are cross-sectional views illustrating the operation of the valve ring and the valve body.

(A) is a top view, (b), (c) is sectional drawing, (d) is a side view of the valve body of FIG.

8 (a) to (c) are explanatory views of the operation of the valve, and a developed view showing the state of the air supply and exhaust by the cross section of the cylinder and the valve body;

9 is a conventional belt type grinding tool.

※ Explanation of symbols for main parts of drawing

1: tension bar 2: driven pulley

3: pulley holding member 4, 26: shaft

5, 10: screw 6: adjusting screw

7, 19: spring 8: housing

8c: long hole 9: tube member

11: notch 12, 42: pin

13: Small diameter 14: Wonju groove

15, 23, 46: protrusion 16: spring bearing member

17: tension spring 18: push button

20: tension pulley 21: offset bracket

22, 45: guide groove 24: cylinder

25: wheel 26: shaft

27: bearing 28: drive pulley

29: nut 30: euro

31, 39, 40: hole 32: cover

33: valve body 34: valve ring

35: retaining ring 36: ring nut

37: first air supply passage 38: second air supply passage

41, 48: sealing 43, 53: exhaust passage

47: home 49: stopper

50: stopper ring 50a: passage part

50b: step 51: slope

Claims (7)

A driven pulley attached to the tip of the tension bar freely attached to the housing, A belt-type grinding tool in which an endless grinding belt is installed in a driving pulley attached to an air motor attached to the housing, and the rotary belt can be driven by the air motor. A valve for supplying / exhausting air to the air motor is installed in a housing of the belt type grinding tool, The valve is composed of a valve body that is rotatably fixed to the housing and a valve ring that is relatively rotatable and slidably attached to the valve body to supply or exhaust air to the air motor, The air motor can be rotated or stopped by advancing or retracting the valve ring, and the valve ring is rotated to the right or left by integrating the valve ring with the valve body in the state where the valve ring is advanced. Belt-type grinding tool, characterized in that the rotation of the power to reverse or reverse. A driven pulley attached to the tip of the tension bar freely attached to the housing, A belt-type grinding tool in which an endless grinding belt is installed in a driving pulley attached to an air motor attached to the housing, and the rotary belt can be driven by the air motor. A valve for supplying / exhausting air to the air motor is installed in a housing of the belt type grinding tool, The valve is composed of a valve body which is rotatably fixed to the housing, and a valve ring that is relatively rotatable and slidably attached to the valve body, wherein the valve body forms an air supply passage and an air exhaust passage. An inner circumferential surface of the valve ring has an annular groove for communicating the air supply passage formed on the valve body side to an air source, a sealing ring for blocking an air source on both sides of the annular groove, and an axial direction of the valve body. Forming a projection to be freely fitted in the guide groove formed, and advancing the valve ring along the guide groove of the valve body so that the air supply passage communicates with an air source through the annular groove. Rotating the valve ring to the right or left side by interlocking the valve body through the projection The air supply passage formed in the valve body communicates with the air supply / exhaust hole of the air motor attached in the housing through the air supply / exhaust hole provided in the housing, and the air motor can be electrostatically reversed. Belt type grinding tool characterized by the above-mentioned. The method of claim 2, A stopper made of an elastic body is provided at one end of the valve ring, and an inclined surface protruding inward is formed on an inner circumferential surface of the opposite housing, and a pass portion through which the stopper can pass is provided on the inclined surface, and the valve ring is It is possible to advance the valve ring only when the stopper is in a position opposite to the passage, and the valve ring allows the stopper to retract the valve ring over the inclined surface at any position. tool. The method of claim 3, wherein And a ring member having the passage portion and the inclined surface formed on an inner circumferential surface of the end portion of the housing. The method according to any one of claims 2 to 4, The tension bar has a belt type grinding tool, characterized in that it is provided with a lock mechanism for locking the tension bar in the state in which the tension bar is pushed. The method according to any one of claims 2 to 4, A belt type grinding tool according to claim 1, wherein an offset bracket having a tension pulley can be detachably attached to the housing by changing a position on the housing. The method of claim 5, wherein A belt type grinding tool according to claim 1, wherein an offset bracket having a tension pulley can be detachably attached to the housing by changing a position on the housing.