TW201736038A - Belt-type grinding tool - Google Patents

Abstract

Provided is a belt-type grinding tool in which foreign matter is prevented from entering the interior of a tool body. A pulley support bar (12) is held by a bar containment hole (29) in the tool body (10) so as to be capable of sliding between a tension imparting position at which tension is applied to an endless grinding belt (20) and a tension release position at which the pulley support lever (12) is retracted from the tension imparting position and the tension on the endless grinding belt is released. A latching member containment hole (33), which has a circular cross-section and which is substantially orthogonal to the bar containment hole (29), is formed in the tool body (10), and a substantially cylindrical latching member (34) is slidably positioned in the latching member containment hole (33). The latching member (34) is capable of being displaced between a latching position at which the pulley support bar (12) is latched so as to be held in the tension release position, and an unlatching position at which the pulley support bar (12) is unlatched and can be displaced between the tension imparting position and the tension release position. An annular seal member (38) is positioned between the outer peripheral surface (34a) of the latching member (34) and the inner peripheral surface (33c) of the latching member containment hole (33).

Description

Belt grinding tool

The present invention relates to a belt type grinding tool, and more particularly to a belt type grinding tool having a structure for holding a pulley support rod in a retracted position when an annular grinding belt is exchanged.

The belt grinding tool includes: a drive pulley that is rotationally driven by a motor, a rotatable idler pulley, and an annular grinding belt that is wound between the drive pulley and the idle pulley. A grinding tool that grinds the object by abutting the annular grinding belt that is rotationally driven by the rotation of the drive pulley against the object. The pulley support lever that supports the idle pulley is slidably held in the front-rear direction on the tool body provided with the drive pulley, and is urged toward the front by a spring provided in the tool body. By the pushing force of the spring, the idle pulley is pushed against the inner peripheral surface of the annular grinding belt, and moderate tension is applied to the annular grinding belt wound around the drive pulley and the idle pulley.

If the ring-shaped grinding belt is used to some extent, it needs to be exchanged. In order to exchange, and in order to liberate the tension applied to the ring-shaped grinding belt, the pulley-supporting rod is pressed against the pushing force of the spring, and it is necessary to press the belt. The state is maintained. Therefore, a locking structure for holding the pulley support lever at a position to be retracted is usually provided. For example, in the patent document 1, an opening that communicates the pulley support lever with the internal space that is slidably held is formed in the tool body, and an L-shaped locking member (button) is disposed in the opening, and the locking member is locked. The pulley support rod is held in the retracted position by the pulley support rod.

[Practical Technical Literature] [Patent Document]

[Patent Document 1] Japanese Patent No. 3711095

However, since the locking member is movable to the tool body, a gap occurs between the tool body and the button. In this case, foreign matter such as grinding powder and dust enters the inside of the tool body from this gap. When such a foreign matter enters the sliding portion between the pulley support rod and the tool body, for example, the displacement of the pulley support rod is impaired, and there is a problem in that it is impossible to apply a suitable tension to the annular grinding belt.

Here, the present invention has been made in view of the above problems in the prior art, and an object thereof is to provide a belt type grinding tool for preventing foreign matter from intruding into a gap between a locking member that locks a pulley supporting lever and a tool body. Inside the tool body.

In other words, the present invention provides a belt type grinding tool comprising: a pulley support rod extending in a direction from a front end portion to a rear end portion in a longitudinal axis, and having an idling belt rotatably attached to the front end portion And a tool body provided with a drive pulley that is rotationally driven by the motor, and has a rod receiving hole for receiving the rear end portion of the pulley support rod, and a cross section substantially perpendicularly intersecting the rod receiving hole a circular locking member receiving hole, the pulley supporting rod is provided with a tension applying position to the annular grinding belt wound between the idle pulley and the driving pulley, and from the tension The tension imparting position retreats the tension liberation position of the annular grinding belt to be slidably held in the direction of the length axis; and the tension imparting spring is disposed between the pulley support rod and the tool body, The pulley support rod is urged toward the tension applying position; and the locking member is a substantially cylindrical locking member slidably disposed in the locking member receiving hole, and the locking member receiving hole is provided in the locking member receiving hole in Fixing the pulley support lever in the tension release position to the locking position of the pulley support lever at the tension release position, and releasing the engagement of the pulley support lever at the tension applying position and The locking position of the variable position between the tension releasing positions is variable between the positions; and the annular sealing member is disposed on the outer circumferential surface of the locking member and the inner circumference of the locking member receiving hole Between the faces.

In the belt type grinding tool, since the sealing member is disposed between the outer circumferential surface of the locking member and the inner circumferential surface of the locking member accommodation hole, foreign matter such as grinding powder and dust can be prevented from the locking member and the tool. The gap between the bodies invades the inside of the tool body. Moreover, the ring-shaped denseness is formed between the substantially cylindrical locking member and the circular locking member holding hole. Since the sealing member is sealed, the sealing member is uniformly adhered to the locking member and the tool body, and the sealing state is easily maintained. Further, since there is no corner portion in the portion in contact with the sealing member, stress concentration toward the sealing member is less likely to occur, and the sealing member is less likely to be damaged. Further, since the substantially cylindrical locking member is held by the locking member receiving hole having a circular cross section, it is easy to reduce the swimming of the locking member as compared with the conventional plate-shaped locking member. Thereby, the state in which the gap between the locking member and the tool body is blocked can be more reliably maintained, and it is possible to more reliably prevent foreign matter from entering the inside of the tool body.

Preferably, the sealing member has an inner peripheral portion that is in close contact with the outer peripheral surface of the locking member, an outer peripheral portion that is in close contact with the inner peripheral surface of the locking member holding hole, and the inner circumference. The flexible portion that can be relatively displaced in the direction in which the outer peripheral portion is directed toward the central axis of the sealing member may be used.

According to this configuration, when the locking member is displaced, the inner peripheral portion and the outer peripheral portion are displaced by the respective following locking members and the tool body, so that the sealing member and the locking member and the tool body can be more reliably maintained. Closed state.

Preferably, the locking member has an annular sealing member holding groove on the outer peripheral surface, and the locking member holding hole has an enlarged diameter portion that expands in diameter on an outer surface of the tool body, and the sealing member The inner peripheral portion may be held in the sealing member holding groove, and the outer peripheral portion may be disposed in close contact with the enlarged diameter portion of the locking member holding hole.

With this configuration, it is possible to further maintain the density The sealing state between the sealing member and the locking member and the tool body.

Preferably, the pulley support bar has a locking groove formed at the rear end portion, and the locking member has a through hole passing through the rear end portion of the pulley support rod, and the through hole is provided with a through hole a locking protrusion that protrudes inwardly from a part of the inner circumferential surface thereof, and the card supporting member is displaced toward the locking position in a state where the pulley supporting lever is located at the tension releasing position, and the card of the locking member is The stopper protrusion is engaged with the locking groove, and the pulley support lever may be held at the tension release position.

Further preferably, the locking spring may be provided between the tool body and the locking member, and the locking member may be urged toward the locking position.

Hereinafter, an embodiment of the belt type grinding tool of the present invention will be described based on the drawings.

1‧‧‧Band grinding tool

10‧‧‧Tool body

10a‧‧‧ back end

10b‧‧‧Outside

12‧‧‧wheel support rod

12a‧‧‧ front end

12b‧‧‧ back end

12c‧‧‧Spring receiving hole

12d‧‧‧ long hole

12e‧‧‧ card ditch

14‧‧‧ Cover

14a‧‧‧ Pressing the protrusion

16‧‧‧ drive pulley

18‧‧‧ idling pulley

19‧‧‧Air motor

19a‧‧‧Drive shaft

20‧‧‧Round grinding belt

22‧‧‧Operator

24‧‧‧Air supply port

26‧‧‧Air supply road

28‧‧‧Adjustment agency

29‧‧‧ rod receiving hole

30‧‧‧Tension imparting spring

32‧‧‧Bolts

33‧‧‧Clock member receiving hole

33a‧‧‧Expanding Department

33b‧‧‧ bottom

33c‧‧‧ inner circumference

34‧‧‧Clocking members

34a‧‧‧ outer perimeter

34b‧‧‧ Sealing member retaining groove

34c‧‧‧through hole

34d‧‧‧Spring Holder

34e‧‧‧Snap protrusion

36‧‧‧Lock spring

38‧‧‧ Sealing members

38a‧‧‧ Inner Week

38b‧‧‧The outer part

38c‧‧‧Flexible

42‧‧‧Installation bolts

L‧‧‧length axis

M‧‧‧ center axis

[Fig. 1] A side view of the pulley support bar of the belt type grinding tool according to the embodiment of the present invention when it is placed at a tension applying position.

[Fig. 2] A side view showing a state in which the cover of the belt type grinding tool of Fig. 1 is removed.

[Fig. 3] A top cross-sectional view taken along line III-III of Fig. 1.

[Fig. 4] A front cross-sectional view taken along line IV-IV of Fig. 1.

[Fig. 5] An enlarged view of the periphery of the locking member of the belt type grinding tool of Fig. 3.

[Fig. 6] The front view of the locking member.

[Fig. 7] A cross-sectional view of the sealing member.

[Fig. 8] A side view of the pulley support bar of the belt type grinding tool of Fig. 2 when it is at the tension release position.

[Fig. 9] A top cross-sectional view taken along line IX-IX of Fig. 8.

The belt grinding tool 1 according to the embodiment of the present invention includes a tool body 10, a pulley support rod 12 held by the tool body 10, and a tool attached to the tool, as shown in Figs. 1 and 2 The cover 14 of the main body 10, the drive pulley 16 attached to the tool body 10 inside the cover 14, and the idle pulley 18 rotatably attached to the front end portion 12a of the pulley support rod 12. The drive pulley 16 is fixed to the drive shaft 19a of the air motor 19 disposed in the tool body 10 as shown in Fig. 3, and is driven to rotate by the air motor 19. Between the drive pulley 16 and the idle pulley 18, an annular grinding belt 20 is wound. By operating the operating lever 22 pivotally provided to the tool body 10, the supplied air from the air supply port 24 in the rear end portion 10a of the tool body 10 is introduced into the air motor 19 through the air supply path 26. By the compressed air, the air motor 19 is rotationally driven, and the ring-shaped grinding belt 20 is rotationally driven by the drive pulley 16.

As shown in FIG. 3, the pulley support rod 12 extends in the direction of the longitudinal axis L from the distal end portion 12a that rotatably holds the idle pulley 18 to the rear end portion 12b that is housed in the tool body 10 . The front end portion 12a is provided with an adjustment mechanism 28 for finely adjusting the angle of the idle pulley 18 for the longitudinal axis L. The rear end portion 12b has a cylindrical shape and is slidably held in the direction of the longitudinal axis L of the rod housing hole 29 provided in the tool body 10. The rear end portion 12b is formed with a spring receiving hole 12c extending forward from the rear end, and a tension applying spring 30 is disposed in the spring receiving hole 12c. By the tension imparting spring 30, the pulley support lever 12 is urged toward the front of the tool body 10 (to the left as seen from the figure). In the state shown in Figs. 1 to 3, the idle pulley 18 is pressed against the inner peripheral surface of the annular grinding belt 20 by the biasing force of the tension applying spring 30, and the tension is applied to the annular grinding belt 20. . Further, a long hole 12d extending in the direction of the longitudinal axis L is formed in the rear end portion 12b of the pulley support rod 12. As is understood from Fig. 4, the tip end of the bolt 32 attached to the tool body 10 is received therein. Long hole 12d. Thereby, the pulley support bar 12 is the position of the variable position in the direction of the longitudinal axis L with respect to the tool body 10, which is limited by the length in the direction of the longitudinal axis L of the long hole 12d, and the length axis L The rotation in the surroundings is blocked.

In the tool body 10, as shown in detail in FIG. 5, a circularly-shaped locking member accommodation hole 33 extending in a direction substantially perpendicular to the rod accommodation hole 29 is formed, and is disposed in the locking member accommodation hole 33. There is a substantially cylindrical locking member 34. As shown in Fig. 6, the locking member 34 has an annular seal member holding groove 34b formed on the outer peripheral surface 34a thereof, a through hole 34c penetrating the center portion, and an upper spring holding portion 34d. The through hole 34c has an elliptical shape that is slightly elongated, and a crescent-shaped locking protrusion that protrudes inward is formed at an upper central position of the inner peripheral surface thereof. From 34e. The locking spring 36 is set between the tool body 10 and the spring holding portion 34d of the locking member 34. The locking member 34 is urged toward the side (the lower side as seen from Figs. 3 and 5) by the locking spring 36.

An annular seal member 38 is attached between the locking member 34 and the tool body 10. The sealing member 38 has a shape as shown in Fig. 7 in a state where no external force is applied, and includes an inner peripheral portion 38a and an outer peripheral portion 38b, and the inner peripheral portion 38a and the outer peripheral portion 38b toward the sealing member. The direction of the central axis M of 38 can be formed by a curved flexible portion 38c that is coupled to the oppositely displaced position. As shown in FIG. 5, the inner peripheral portion 38a is in a state of being adhered to the outer peripheral surface 34a of the locking member 34 in the sealing member holding groove 34b of the locking member 34. The locking member accommodation hole 33 of the tool body 10 is an enlarged diameter portion 33a having a diameter enlarged on the outer surface 10b of the tool body 10, and the outer peripheral portion 38b is an inner peripheral surface of the enlarged diameter portion 33a and the locking member accommodation hole 33. 33c close. More specifically, the outer peripheral portion 38b is pressed against the bottom surface 33b of the enlarged diameter portion 33a and is also in close contact with the inner peripheral surface 33c of the enlarged diameter portion 33a. In the state of FIG. 5, the inner peripheral portion 38a of the seal member 38 is retracted toward the inside of the tool body 10 together with the locking member 34, but the outer peripheral portion 38b is locked to the enlarged diameter portion of the locking member receiving hole 33. 33a and its position is maintained.

In the state of FIGS. 1 to 3, the pulley support lever 12 is located at a tension applying position that is urged forward by the tension applying spring 30 and tension is applied to the annular grinding belt 20, and the locking member 34 is provided. It is a locking release position in which the displacement in the direction of the longitudinal axis L of the pulley support lever 12 is permitted. The pulley support rod 12 is oriented in a state where the cover 14 is removed The rear side (the right side as shown in the figure) is pushed in against the biasing force of the tension applying spring 30, and the locking groove 12e provided in the rear end portion 12b of the pulley supporting rod 12 is integrated with the locking projection 34e of the locking member 34. When the position is displaced, as shown in Fig. 9, the locking member 34 is displaced from the lower side as seen from the figure by the biasing force of the locking spring 36, and the card is engaged with the locking groove 34e by the locking projection 34e. Stop position. Thus, the locking protrusion 34e of the engaging member 34 is engaged with the locking groove 12e, and the pulley supporting lever 12 is held at the tension releasing position. At this time, the distance between the idle pulley 18 and the drive pulley 16 is close to the state in which the tension is not applied to the annular grinding belt 20. The inner peripheral portion 38a of the sealing member 38 is slightly pushed out toward the outside of the tool body 10 together with the locking member 34, but the outer peripheral portion 38b is maintained in close contact with the enlarged diameter portion 33a of the locking member accommodation hole 33. . Moreover, the cover 14 attached to the tool body 10 by the attachment bolt 42 has a pressing protrusion 14a (Fig. 5) that protrudes toward the locking member 34 at a position where it is integrated with the locking member 34, and the cover 14 is attached thereto. In the state in which the locking member 34 is prevented from being displaced toward the locking position by the pressing protrusion 14a, the pulley supporting lever 12 is not held by the locking member 34 at the tension releasing position. Therefore, in order to lock the pulley support lever 12 to the tension release position, it is necessary to remove the cover 14.

When the pulley support lever 12 is maintained at the tension release position by the locking member 34 as shown in Figs. 8 and 9, the exchange of the annular grinding belt 20 can be easily performed. When the ring-shaped grinding belt 20 is mounted between the drive pulley 16 and the idle pulley 18 to push the locking member 34, the locking between the locking projection 34e and the locking groove 12e is released, and the pulley is supported. The rod 12 is displaced by the biasing force of the tension applying spring 30, and is returned to the tension applying position shown in Figs. 1 to 3 again, and the tension is applied to the ring-shaped grinding belt 20. At this time, the locking projections 34e of the locking member 34 are pressed against the outer circumferential surface of the pulley support lever 12 by the locking springs 36.

When the belt type grinding tool 1 is used, the cover 14 that covers the drive pulley 16 from the side is attached for safety. When the cover 14 is attached to the tool body 10, the locking member 34 is pressed by the pressing protrusion 14a. Therefore, when the locking member 34 is in the locking position when the cover 14 is attached, the locking member 34 is pressed against the pressing protrusion 14a of the cover 14 and is forcibly displaced toward the locking release position. Further, as shown in FIG. 5, the locking projection 34e of the locking member 34 is a position slightly away from the outer circumferential surface of the pulley support lever 12.

Between the locking member 34 and the tool body 10, an annular sealing member 38 is attached, and the gap between the locking member 34 and the tool body 10 is blocked by the sealing member 38. Thereby, foreign matter such as grinding powder and dust is prevented from entering the inside of the tool body 10 through the gap. Further, the sealing member 38 has a structure in which the inner peripheral portion 38a, the outer peripheral portion 38b, and the flexible portion 38c are provided, and the inner peripheral portion 38a and the card are displaced even when the locking member 34 is displaced between the locking position and the unlocking position. Since the contact state of the stopper member 34 and the adhesion state of the outer peripheral portion 38b and the tool body 10 are maintained, the displacement between the locking position and the unlocking position of the locking member 34 is not caused, and the foreign matter can be prevented from time to time. Intrusion. Further, since the locking member 34, the locking member receiving hole 33, and the sealing member 38 are all integral Since the circular shape is easy to maintain the close contact state, for example, even if the locking member 34 is swung, it is difficult to form a gap with the sealing member 38. Further, since the portion that is in contact with the sealing member 38 has no corner portion, stress concentration is less likely to occur in the sealing member 38. Further, since the cylindrical locking member 34 is held by the locking member accommodation hole 33 having a circular cross section, it is easy to reduce the locking of the locking member 34 as compared with the conventional plate-shaped locking member. Swimming in the member receiving hole 33. As described above, in the belt type grinding tool 1, the locking member 34, the locking member accommodation hole 33, and the sealing member 38 are all formed into a circular shape, so that the locking member 34 can be more reliably inserted and A gap between the tool bodies 10.

Further, in the above embodiment, the driving source of the driving pulley is an air motor, but an electric motor may be used.

1‧‧‧grinding tools

10‧‧‧Tool body

10a‧‧‧ back end

12‧‧‧Air motor

12a‧‧‧ Output shaft

16‧‧‧wheel support rod

18‧‧‧ idling pulley

20‧‧‧Round grinding belt

22‧‧‧ grip

24‧‧‧Connectors

28‧‧‧Sliding guide members

32‧‧‧ Spring

34‧‧‧ front spring receiving hole

38‧‧‧Spring support members

Claims (5)

A belt type grinding tool comprising: a pulley support rod extending from a front end portion to a rear end portion, and an idling pulley rotatably attached to the front end portion; and a tool body provided by a driving pulley that is rotationally driven by the motor, the rod receiving hole that accommodates the rear end portion of the pulley supporting rod, and a circular locking member receiving hole that intersects the rod receiving hole substantially perpendicularly a pulley support rod for: applying a tension tensioning position to an annular grinding belt wound between the idle pulley and the driving pulley, and retracting the annular grinding belt from the tension imparting position a tension liberation tension liberation position is slidably held in a direction of a length axis of the pulley support rod; and a tension imparting spring is disposed between the pulley support rod and the tool body, the pulley The support rod is urged toward the tension applying position; and the locking member is a substantially cylindrical locking member slidably disposed in the locking member receiving hole, and the locking member receiving hole is included in the locking member receiving hole Tension liberation The pulley support lever locks the pulley support lever at the locking position of the tension release position, and releases the lock support lever at the tension imparting position and the tension release position. The locking position of the inter-variable position is variable between the two, and the annular sealing member is disposed between the outer circumferential surface of the locking member and the inner circumferential surface of the locking member receiving hole. The belt-type grinding tool according to claim 1, wherein the sealing member has a surface that is in close contact with the outer peripheral surface of the locking member An inner peripheral portion and an outer peripheral portion that is in close contact with the inner peripheral surface of the locking member holding hole, and a direction in which the inner peripheral portion and the outer peripheral portion are relatively displaced toward a central axis of the sealing member Flexible section. The belt-type grinding tool according to claim 2, wherein the locking member has an annular sealing member holding groove on the outer peripheral surface, and the locking member retaining hole is provided outside the tool body The enlarged diameter portion of the enlarged diameter on the side surface, the inner peripheral portion of the sealing member is held in the sealing member holding groove, and the outer peripheral portion is disposed in close contact with the enlarged diameter portion of the locking member holding hole . The belt grinding tool according to any one of claims 1 to 3, wherein the pulley support rod has a locking groove formed at the rear end portion, and the locking member has a pulley passing therethrough a through hole of the rear end portion of the support rod, wherein the through hole is provided with a locking protrusion that protrudes inward from a part of the inner circumferential surface thereof, and the pulley support rod is located at the tension release position by the card The stopping member is displaced toward the locking position, and the locking protrusion of the locking member is engaged with the locking groove to hold the pulley supporting lever at the tension releasing position. The belt type grinding tool according to claim 4, further comprising: a locking spring that is set between the tool body and the locking member and that urges the locking member toward the locking position.