JP5278855B2 - Pipe connection structure - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a practical pipe connection structure which does not need any rotation operation of a pipe and is free from risk of the pipe being unexpectedly disconnected. <P>SOLUTION: An engagement receiving part 17 is provided in an outer peripheral surface of an inside pipe 6. A tool insertion hole 28 and an elastic lock arm 18 are arranged in an outside pipe 11. The lock arm 18 is provided with a lock part 23 for engaging with the engagement receiving part 17 and fixing both the pipes 6, 11 to prevent coming-off and a cancel operation part 24 protruding into the tool insertion hole 28. As a rod-like tool 32 is inserted into the tool insertion hole 28, the cancel operation part 24 is pressed and an engaging state of the lock part 23 for the engagement receiving part 17 is canceled. <P>COPYRIGHT: (C)2010,JPO&amp;INPIT

Description

  The present invention relates to a pipe connection structure.

  As a portable air blower, a power blower suitable for efficiently performing gathering work such as fallen leaves and garbage is known. The power blower includes a prime mover such as an internal combustion engine and a centrifugal blower driven by the prime mover. An air outlet is formed in the casing of the centrifugal blower, and an air outlet pipe having an appropriate length is detachably connected to the air outlet.

As a technique applicable to the connection structure of the said wind pipe with respect to the said wind outlet, the thing of a various aspect is well-known as described in patent documents 1-6, for example.
Japanese Patent No. 3519021 Japanese Utility Model Publication No. 42-13881 Japanese Utility Model Publication No. 42-8297 Japanese Utility Model Publication No. 63-42365 US Pat. No. 6,640,384 JP 2006-34684 A

  It is desired that the connection structure of the wind pipe with respect to the air outlet satisfies the following conditions.

  First, it is preferable that the discharge pipe can be easily connected and fixed. In particular, a connection method that does not require the rotation operation of the wind pipe is preferable. This is because the air blowing pipe is thick and difficult to grasp, and its rotation operation is complicated. When the discharge pipe is long, its rotation operation becomes more difficult.

  On the other hand, it is preferable that the discharge pipe be removed without intentional use of a tool. During the air blowing operation, the air blowing fan rotates at a high speed behind the air outlet. For this reason, it is dangerous if the wind pipe is accidentally disconnected. This request is consistent with recent safety regulations.

  Furthermore, a mode that does not require a screw for fixing the discharge pipe or the like is preferable. This is because there are problems such as losing or forgetting fixing screws, and screw tightening operations are troublesome.

  However, the conventionally known connecting structure does not satisfy all of the above conditions.

  The present invention has been made with the above circumstances as an opportunity, and intends to propose a pipe connection structure that satisfies all of the above conditions and has high practicality.

  In order to solve the above problems, a pipe connection structure according to the present invention is a pipe connection structure in which an end portion of an inner pipe is fitted into an end portion of an outer pipe to prevent it from being detached, and is provided on an outer peripheral surface of the inner pipe. An engagement receiving portion is provided, and a tool insertion hole and an elastic lock arm are provided in the outer pipe, and the lock arm is pushed by the inner pipe when the pipes are fitted and escaped. A rod-shaped tool that includes a lock portion that engages with the engagement receiving portion by the elasticity to prevent the pipes from coming off and is fixed, and a release operation portion that projects into the tool insertion hole, and is inserted into the tool insertion hole; The release operation part is pushed, and the engagement state of the lock part with respect to the engagement receiving part is released (Claim 1).

  In the present invention, the connecting operation of the two pipes is performed as follows. The end portion of the inner pipe is fitted in the end portion of the outer pipe in the axial direction. In the fitting process, the inner pipe moves toward the inner side of the outer pipe while pushing away the lock portion of the lock arm. When the engagement receiving portion reaches the position of the lock portion, the lock portion engages with the engagement reception portion due to elasticity of the lock arm. As a result, the inner pipe is secured to the outer pipe.

  The work of removing the inner pipe is performed as follows. A rod-like tool such as a screwdriver is inserted into the tool insertion hole. Thereby, the said release operation part is pushed with the said rod-shaped tool, and the engagement state of the said lock part with respect to the said engagement receiving part is cancelled | released. Therefore, the inner pipe is pulled out from the outer pipe.

  According to the present invention, the mutual connection and retaining prevention are completed only by fitting both the pipes in the axial direction. Therefore, the connecting work is easy.

  Also, the inner pipe cannot be removed unless intentionally used with a tool. Therefore, there is no fear that the inner pipe will come off unexpectedly. And since a locked state is cancelled | released only by inserting a rod-shaped tool in the said tool penetration hole, the operativity at the time of cancellation | release is also good.

  Furthermore, no screws are required for securing the inner pipe to prevent it from coming off. Therefore, there is no problem such as loss or forgetting to attach screws.

  As a preferred embodiment, in the state where the engagement state of the lock portion with respect to the engagement receiving portion is released by the insertion of the rod-like tool into the tool insertion hole, the release is performed by the elasticity of the lock arm. It can also be set as the aspect by which the said rod-shaped tool is hold | maintained by hand between an operation part and the inner surface of the said tool penetration hole. According to this embodiment, since the operator's hands are free when the locked state is released, the inner pipe can be easily and reliably extracted.

  As a preferred embodiment, an aspect in which a wedge-shaped protrusion that abuts on the inner surface of the outer pipe and eliminates radial play between the two pipes in a retaining state is disposed on the outer peripheral surface of the inner pipe. (Claim 3). According to this embodiment, there is no backlash in the radial direction between the two pipes in the retaining fixed state, which is preferable.

  As a preferred embodiment, an elastic push-back portion is disposed between the pipes to urge the inner pipe in the anti-fitting direction so as to eliminate axial play between the pipes in the retaining state. It can also be set as the aspect currently provided (Claim 4). According to this embodiment, there is no backlash in the axial direction between the two pipes in the retaining prevention fixed state, which is preferable.

  As a preferred embodiment, an axial guide groove is formed on the inner peripheral surface of the outer pipe, and a protrusion that fits the guide groove is formed on the outer peripheral surface of the inner pipe. It is also possible to adopt a mode in which the front end portion of the guide groove is an inclined surface and the back wall portion of the guide groove is the elastic push-back portion that pushes back the inclined surface.

  Various embodiments are conceivable as specific examples of the lock arm. For example, the lock arm includes a pivot shaft portion rotatably supported by the outer pipe between the lock portion and the release operation portion. And an elastic return arm portion that elastically returns the lock portion to the engagement position with the engagement receiving portion may extend from the pivot shaft portion (claim 6).

  As another specific example of the lock arm, a cantilever support portion supported in a cantilever manner on the outer pipe is provided on one end side, and the other end portion is the lock portion, and the cantilever support portion and the lock are provided. It is also possible to adopt an aspect in which an elastic part and the release operation part are provided between the parts (claim 7).

  As another specific example of the lock arm, a U-shaped or V-shaped one having an elastic folded portion between two arm portions may be mentioned. In this case, one arm portion is supported by the outer pipe, the end portion of the other arm portion is the lock portion, and the release operation portion is provided between the elastic folded portion and the lock portion. 8).

  As a preferred embodiment, the lock arm can be attached to and detached from the outer pipe (claim 9). In this way, when the lock arm is broken, it can be replaced with a lock arm having the same configuration as the lock arm. Since the outer pipe can be used as it is and only the lock arm can be replaced, the repair cost can be reduced.

  As a preferred embodiment, the lock arm is an integral lock arm formed integrally with the outer pipe, and the outer pipe has an attachment portion for attaching an exchange lock arm in place of the integral lock arm. It can also be set as the aspect formed (Claim 10). In this way, when the integrated lock arm is damaged, it can be replaced with the replacement lock arm using the mounting portion. For this reason, the outer pipe can be used as it is, and the repair cost can be reduced.

  Embodiments of the present invention will be described below with reference to the accompanying drawings.

  1 is an overall perspective view showing a usage state of a power blower including a pipe connection structure according to an embodiment of the present invention, FIG. 2 is an enlarged perspective view of a pipe in FIG. 1 in an unconnected state, and FIG. FIG. 4 is a cross-sectional view taken along the line IV-IV in FIG. 2, FIG. 5 is a side view of the connecting process of the pipe in FIG. 2, and FIG. 6 is a side view of the pipe in FIG. FIG. 7 is a side view of the pipe connection structure of FIG. 6 when the pipe is removed.

  A power blower 1 in FIG. 1 is a hand-held type, and is detached from a small air-cooled internal combustion engine 3 as a prime mover, a centrifugal blower 4 driven by the internal combustion engine 3, and a vent 5 of the blower 4. An air discharge pipe 6 that can be connected is provided. Further, the power blower 1 can be operated with a handle 8 for holding an airframe 7, which is a combined body of the internal combustion engine 3 and the blower 4, with one hand and a finger of the hand holding the handle 8. A special throttle trigger 9 is attached. As shown in FIG. 1, the operator holds the handle 8 with one hand and controls the output of the internal combustion engine 2 with the throttle trigger 9, and the fallen leaves L are generated by the high-speed airflow W that blows out from the discharge pipe 6. And so on.

  The power blower 1 includes a pipe connection structure 10 according to an embodiment of the present invention. Specifically, the pipe connection structure 10 is applied to a connection portion between the fan case pipe 11 having the air outlet 5 and the air outlet pipe 6. However, this is an example for convenience of description, and the pipe connection structure according to the present invention can of course be applied to pipe connection portions in various apparatuses.

  As shown in FIG. 2, the fan case pipe 11 is formed integrally with the fan case 12 of the centrifugal blower 3, and the front end opening of the fan case pipe 11 serves as the air outlet 5. The fan case 12 is formed by joining the left and right halves at a mating surface and connecting and fixing them with bolts 13. The fan case pipe 11 is formed by a combination of left and right semi-cylindrical portions 11L and 11R included in the left and right halves, respectively.

  In the present embodiment, the fan case pipe 11 is an outer pipe, the air discharge pipe 6 is an inner pipe, and the rear end portion 6r of the air discharge pipe 6 is fitted into the front end portion 11f of the fan case pipe 11. And is secured.

  An engagement protrusion 14, a wedge-shaped protrusion 15, and a guide protrusion 16 are disposed on the air discharge pipe 6 that is an inner pipe. The air discharge pipe 6 is made of plastic.

  The engagement protrusion 14 is integrally formed on the lower surface of the outer peripheral surface of the connection side end 6r of the air discharge pipe 6. The surface of the engagement protrusion 14 on the side opposite to the fitting direction is an engagement receiving portion 17, which is a surface perpendicular to the axis X of the air discharge pipe 6. This is to ensure engagement with the lock arm 18 described later. On the other hand, the surface on the fitting direction side of the engagement protrusion 14 is an inclined surface 19 so that the lock arm 18 can be easily pushed away when the pipes 6 and 11 are fitted together.

  The wedge-shaped protrusion 15 is formed on the lower surface of the air discharge pipe 6. The wedge-shaped protrusion 15 is disposed at a position closer to the air discharge tip portion of the air discharge pipe 6 than the engagement protrusion 14. The wedge-shaped protrusion 15 abuts against the inner surface of the fan case pipe 11 when the discharge pipe 6 and the fan case pipe 11 are connected, and there is no play in the radial direction and the axial direction between the pipes 6 and 11. Has the effect of

  The guide ridges 16 are formed on the left and right sides of the air discharge pipe 6 and extend in the direction of the axis X of the air discharge pipe 6.

  On the other hand, the fan case pipe 11 which is an outer pipe is provided with a guide groove 20, an engagement protrusion receiving groove 21 and a box-shaped lock arm accommodating portion 22. The fan case pipe 11 is also made of plastic like the air discharge pipe 6.

  The guide grooves 20 are formed on the left and right sides of the fan case pipe 11 and extend in the direction of the axis X of the fan case pipe 11. The guide groove 20 and the guide ridge 16 of the air discharge pipe 6 are compatible with each other. The guide groove 20 and the guide protrusion 16 have two actions. The first action is to reliably guide the fitting of the discharge pipe 6 into the fan case pipe 11 in the direction of the axis X, and the second action is the fitting state of the pipes 6 and 11. The relative rotation around the axis X is restricted.

  The engaging protrusion receiving groove 21 is formed in the lower part of the fan case pipe 11 and extends in the axis X direction of the fan case pipe 11. The engaging protrusion receiving groove 21 receives the engaging protrusion 14 when the air discharge pipe 6 is fitted into the fan case pipe 11. Therefore, the engagement protrusion 14 and the engagement protrusion receiving groove 21 have the same two actions as the combination of the guide protrusion 16 and the guide groove 20.

  The lock arm housing portion 22 is formed integrally with the lower portion of the fan case pipe 11 and extends in the axis X direction of the fan case pipe 11. The hollow interior of the lock arm housing portion 22 communicates with the engagement protrusion receiving groove 21. The lock arm accommodating portion 22 is formed by a combination of left and right box halves 22L and 22R formed integrally with the lower portions of the left and right semicylindrical portions 11L and 11R. The lock arm 18 is disposed in the lock arm housing portion 22 when the fan case 12 is assembled.

  As shown in FIG. 3, in the present embodiment, the lock arm 18 includes a lock portion 23, a release operation portion 24, a pivot shaft portion 25, and an elastic return arm portion 26. The lock portion 23 is formed at the end of the lock arm 18 on the fan case side, and the release operation portion 24 is formed at the opposite end. The pivot shaft portion 25 is formed between the lock portion 23 and the release operation portion 24. The pivot shaft portion 25 extends in a direction perpendicular to the axis X of the fan case pipe 11 and in the horizontal direction on the left and right sides, and as shown in FIG. It is rotatably supported by the bodies 22L and 22R.

  As shown in FIG. 3, the elastic return arm portion 26 extends from the pivot shaft portion 25 toward the fan case 12 at an angle with the lock portion 23. The lower surface 27 of the elastic return arm portion 26 is always in contact with the inner bottom surface 29 of the lock arm housing portion 22. The elastic return arm portion 26 holds the lock portion 23 and the release operation portion 24 in the locked position indicated by a solid line in FIG. 3 due to its elasticity. The lock arm 18 is made of plastic or metal.

  As shown in FIGS. 2 and 3, a tool insertion hole 28 is formed through the lock arm housing portion 22. The tool insertion hole 28 extends in parallel with the pivot shaft 25 of the lock arm 18. The release operation portion 24 of the lock arm 18 protrudes into the tool insertion hole 28 when the fan case pipe 11 is viewed from the left and right sides. When the lock arm 18 is in the locked position indicated by the solid line in FIG. 3, the gap between the lower surface 30 of the release operation portion 24 and the inner surface 31 of the tool insertion hole 28 is inserted into the tool insertion hole 28. It is set smaller than the outer diameter of the rod-like tool 32 (see FIG. 7) such as a screwdriver. For this reason, when the rod-shaped tool 32 is inserted into the tool insertion hole 28, the release operation unit 24 is pushed upward by the outer peripheral surface of the rod-shaped tool 32. As a result, the lock portion 23 rotates downward about the pivot shaft portion 25, and the engagement state between the lock portion 23 and the engagement receiving portion 17 of the engagement protrusion 14 is released. . When the rod-shaped tool 32 is extracted from the tool insertion hole 28, the lock arm 18 is returned to the locked position by the elasticity of the elastic return arm portion 26.

  The operation of the present embodiment will be described with reference to FIGS. 5 to 7, the inside of the lock arm accommodating portion 22 is disclosed in the same manner as in FIG. 3 so that the movement of the lock arm 18 can be seen.

  The connecting operation of the fan case pipe 11 and the air discharge pipe 6 is performed as follows. First, as shown in FIG. 2, the front end of the fan case pipe 11 is aligned with the positions of the engagement protrusion receiving groove 21 and the engagement protrusion 14 and the positions of the guide groove 20 and the guide protrusion 16. The rear end 6r of the discharge pipe 6 is fitted in the axis X direction in the portion 11f.

  In this fitting process, as shown in FIG. 5, the engaging protrusion 14 pushes the lock portion 23 of the lock arm 18 downward from the locked position while moving inside the engaging protrusion receiving groove 21. It moves inward of the fan case pipe 11.

  When the discharge pipe 6 is fully inserted, the engaging projection 14 passes through the lock portion 23, and the lock portion 23 is locked by the elasticity of the elastic return arm portion 26 as shown in FIG. It returns to the hour position and engages with the engagement receiving portion 17. Thereby, the discharge pipe 6 is fixed to the fan case pipe 11 so as not to come off. At the same time, the wedge-shaped protrusions 15 are pressed against the inner surface of the fan case pipe 11 so that there is no play in the radial direction between the pipes 6 and 11 and play in the axis X direction. As a result, there is no backlash between the pipes 6 and 11 in the locking state.

  The work of removing the air discharge pipe 6 is performed as follows. As shown in FIG. 7, a rod-shaped tool 32 such as a screwdriver is inserted into the tool insertion hole 28. As a result, the release operation portion 24 is pushed upward by the rod-shaped tool 32, the lock arm 18 is rotated about the pivot shaft portion 25, and the lock portion 23 with respect to the engagement receiving portion 17 is rotated. The engaged state is released. Therefore, the air discharge pipe 6 may be pulled out from the fan case pipe 11.

  In the state where the engagement state of the lock portion 23 with respect to the engagement receiving portion 17 is released by the insertion of the rod-shaped tool 32 into the tool insertion hole 28, the release operation is performed by the elasticity of the elastic return arm portion 26. The bar-shaped tool 32 is held between the lower surface 30 of the portion 24 and the inner surface 31 of the tool insertion hole 28 in a released state. For this reason, the operator can remove his hand from the bar-shaped tool 32 and extract the wind pipe 6 with both hands. Therefore, the discharge pipe 6 can be easily and reliably extracted.

  In order to make the holding of the bar-shaped tool 32 in the released state more reliable, as shown in FIGS. 3 and 7, the bar-shaped tool 32 is placed on the lower surface 30 of the release operation unit 24 in contact with the bar-shaped tool 32. It is preferable to form a recess for receiving the. A recess for receiving a rod-shaped tool may be formed on the inner surface of the tool insertion hole 28 instead of or together with the lower surface 30 of the release operation portion 24.

  According to the present embodiment, the two pipes 6 and 11 are aligned and fitted in the direction of the axis X to complete their mutual connection and retaining prevention. Therefore, the connecting work is easy.

  Further, the air discharge pipe 6 cannot be removed unless intentionally used with a tool. Therefore, there is no fear that the air discharge pipe 6 may come off unexpectedly during the air blowing operation or the like. Moreover, since the locked state is released simply by inserting the rod-shaped tool 32 into the tool insertion hole 28, the operability at the time of release is also good.

  Furthermore, no screws are required for fixing the discharge pipe 6 to prevent it from coming off. Therefore, there is no problem such as loss or forgetting to attach screws.

  Even if the lock arm 18 is broken, the lock arm accommodating portion 22 may be opened to replace the lock arm alone, so that the continuous use of the pipes 6 and 11 is not hindered.

  In the present embodiment, the fan case pipe 11 is an outer pipe, the air discharge pipe 6 is an inner pipe, and the rear end portion 6r of the air discharge pipe 6 is fitted in the front end portion 11f of the fan case pipe 11. In the above description, the manner in which the stopper is fixed and the stopper is secured is described. However, on the contrary, the fan case pipe 11 may be an inner pipe and the discharge pipe 6 may be an outer pipe. In this case, the components arranged in the fan case pipe 11 are arranged in a discharge pipe serving as an outer pipe, and the components arranged in the discharge pipe 6 are used as a fan case pipe serving as an inner pipe. What is necessary is just to arrange | position.

  Next, another embodiment of the present invention will be described with reference to FIGS.

  8 is a side view of a pipe connection structure according to another embodiment of the present invention, FIG. 9 is an enlarged sectional view taken along the line IX-IX in FIG. 8, and FIG. 10 is an enlarged longitudinal sectional view of FIG. 11 is a cross-sectional view of a pipe connection structure according to still another embodiment of the present invention, and FIG. 12 is a cross-sectional view of a pipe connection structure according to still another embodiment of the present invention.

  In the embodiment of FIG. 8, an elastic push-back portion 33 that eliminates play in the axial direction between the fan case pipe 11 and the air discharge pipe 6 is provided between the fan case pipe 11 and the air discharge pipe 6. The elastic push-back portion 33 urges the discharge pipe 6 in the anti-fitting direction.

  Specifically, as shown in FIG. 9, the elastic push-back portion 33 can be configured by using the guide groove 20 and the guide protrusion 16. That is, as shown in FIG. 9, the front end portion of the discharge pipe 6 in the fitting direction of the guide protrusion 16 is an inclined surface 34 that is inclined toward the center direction of the fan case pipe 11. The back wall portion 33 of the guide groove 20 of the fan case pipe 11 serves as the elastic push-back portion that pushes back the inclined surface 34. As shown in FIG. 8, the back wall portion 33 is elastically connected to the fan case pipe 11 only at the inner side 35 of the fan case pipe 11. Therefore, when the discharge pipe 6 is fitted into the fan case pipe 11, as shown in FIG. 9, the back wall portion 33 is inclined to the inclined surface 34 at the same time that the lock portion is engaged with the engagement receiving portion. Push back elastically. As a result, the contact pressure between the lock portion and the engagement protrusion increases, and there is no play in the axial direction between the pipes 6 and 11 in the retaining state. Therefore, there is no backlash in the axial direction between the pipes 6 and 11.

  The elastic push-back portion 33 may be provided instead of the wedge-shaped protrusion 15 or may be provided together with the wedge-shaped protrusion 15.

  The fan case pipe 11 has an inner taper shape in which the inner diameter of the inner back portion gradually decreases toward the inner back direction, and the taper portion 36 (see FIG. 9) has an action of pushing back the inner end portion of the air discharge pipe 6. If the elastic push-back portion 33 is further provided after being provided, the effect of eliminating the backlash in the axial direction is further improved, which is preferable.

  Next, the embodiment of FIG. 10 includes a lock arm 37 of another mode instead of the lock arm 18, and a lock arm housing portion formed integrally with the fan case pipe 11 corresponding to the lock arm 37. The configuration of 38 is slightly different from that of FIG. 2 (see FIG. 8).

  Unlike the lock arm 18 shown in FIG. 3, the lock arm 37 shown in FIG. Instead, the lock arm 37 of FIG. 10 includes a cantilever support portion 39 supported in a cantilever manner on the lock arm housing portion 38 on one end side. Then, the other end portion that rises vertically is the lock portion 40, and between the cantilever support portion 39 and the lock portion 40, the elastic portion 41 and the release operation portion 42 are sequentially arranged from the cantilever support portion 39 side. Is provided. The lock arm 37 is cantilevered by a lock arm support 43 at the front of the lock arm housing portion 38, and the lock portion 40 is located inside the fan case pipe 11 more than the cantilever support 39. Located on the far side.

In the embodiment of FIG. 10, when the rear end portion 6 r of the air discharge pipe 6 is fitted into the front end portion 11 f of the fan case pipe 11, the engagement protrusion 14 of the air discharge pipe 6 is inclined at the inclined surface 19. It moves toward the inside of the fan case pipe 11 while pushing the lock portion 40 downward. When the discharge pipe 6 is fully inserted, the engagement protrusion 14 passes through the lock portion 40, and the lock portion 40 is engaged with the engagement receiving portion 17 of the engagement protrusion 14 due to the elasticity of the elastic portion 41. Engage with. Thereby, the discharge pipe 6 is fixed to the fan case pipe 11 so as not to come off.
As shown in FIG. 8, a tool insertion hole 44 is formed in the lock arm housing portion 38. The tool insertion hole 44 passes through the lock arm accommodating portion 38 in a horizontal direction perpendicular to the axis of the fan case pipe 11.

  As shown in FIG. 10, the release operation portion 42 of the lock arm 37 protrudes into the tool insertion hole 44 when the fan case pipe 11 is viewed from the left and right sides. A gap between the upper surface 45 of the release operation portion 42 and the inner surface 46 of the tool insertion hole 44 is set smaller than the outer diameter of a rod-like tool such as a screwdriver inserted through the tool insertion hole 44. For this reason, when the rod-shaped tool is inserted into the tool insertion hole 44, the release operation portion 42 is pushed downward by the outer peripheral surface of the rod-shaped tool because the elastic portion 41 is provided. As a result, the lock portion 40 swings downward, and the engagement between the lock portion 40 and the engagement receiving portion 17 is released. When the rod-shaped tool is extracted from the tool insertion hole 44, the lock portion 40 returns to the original position due to the elasticity of the elastic portion 41.

  Also in the embodiment of FIG. 10, the elasticity of the elastic portion 41 in a state where the engagement state of the lock portion 40 with respect to the engagement protrusion 14 is released by the insertion of the rod-shaped tool into the tool insertion hole 44. Thus, the bar-shaped tool is held in a released state between the release operation portion 42 and the inner surface 46 of the tool insertion hole 44. For this reason, the operator can remove the hand pipe from the rod-shaped tool and pull out the air discharge pipe 6 with both hands. Therefore, the discharge pipe 6 can be easily and reliably extracted.

  Next, the embodiment of FIG. 11 is a mode in which a lock arm 47 similar to that of FIG. 10 is disposed in the direction opposite to that of FIG. 10, and the embodiment of FIG. Instead of 14, an engagement recess 48 is provided.

  The lock arm 47 of FIG. 11 includes a cantilever support portion 49 supported in a cantilever manner on the fan case pipe 11 on one end side. The other end rising vertically is the lock portion 50, and the elastic portion 51 and the release operation portion 52 are arranged between the cantilever support portion 49 and the lock portion 50 in this order from the cantilever support portion 49 side. Is provided. The lock arm 47 is cantilevered by a lock arm support portion 54 inside a lock arm housing portion 53 formed integrally with the fan case pipe 11, and the lock portion 50 is different from the example of FIG. Conversely, the fan case pipe 11 is positioned on the outlet opening side of the cantilever support portion 49. Further, in the lock arm 47, the surface on the outlet opening side of the fan case pipe 11 in the lock part 50 is inclined with the inclined surface 55 so that the discharge pipe 6 is easily pushed away when the discharge pipe 6 is fitted. Has been.

  The air discharge pipe 6 fitted into the fan case pipe 11 is formed with the engagement recess 48. The locking portion 50 engages with the engaging recess 48. A surface of the engaging recess 48 on the fitting direction side is an engagement receiving portion 56.

  In the embodiment of FIG. 11, when the rear end portion 6r of the air discharge pipe 6 is fitted into the front end portion 11f of the fan case pipe 11, the air discharge pipe 6 lowers the lock portion 50 on its outer peripheral surface. The fan case pipe 11 moves toward the inner side while pushing away. When the discharge pipe 6 is fully inserted, the engagement receiving portion 56 passes through the lock portion 50, and the lock portion 50 enters the engagement recess 48 due to the elasticity of the elastic portion 51. Then, due to the engagement between the lock portion 50 and the engagement receiving portion 56, the air discharge pipe 6 is fixed to the fan case pipe 11 to prevent it from coming off.

  Also in this embodiment, a tool insertion hole 57 is formed in the lock arm housing portion 53. The tool insertion hole 57 passes through the lock arm housing portion 53 in a horizontal direction perpendicular to the axis of the fan case pipe 11. The release operation portion 52 of the lock arm protrudes into the tool insertion hole 57 when the fan case pipe 11 is viewed from the left and right sides. A gap between the upper surface 58 of the release operation part 52 and the inner surface 59 of the tool insertion hole 57 is set smaller than the outer diameter of a rod-like tool such as a screwdriver inserted through the tool insertion hole 57. For this reason, when the rod-shaped tool is inserted into the tool insertion hole 57, the release operation portion 52 is pushed downward by the outer peripheral surface of the rod-shaped tool because the elastic portion 51 is provided. Thereby, the lock portion 50 swings downward, and the engagement between the lock portion 50 and the engagement receiving portion 56 is released. When the rod-shaped tool is extracted from the tool insertion hole 57, the lock portion 50 returns to the original position by the elasticity of the elastic portion 51.

  Also in the embodiment of FIG. 11, the elasticity of the elastic portion 51 in a state where the engagement state of the lock portion 50 with respect to the engagement receiving portion 56 is released by the insertion of the rod-like tool through the tool insertion hole 57. Thus, the bar-shaped tool is held in a released state between the upper surface 58 of the release operation part 52 and the inner surface 59 of the tool insertion hole 57. For this reason, an operator can take his hand off the bar-shaped tool and pull out the wind pipe 6 with both hands, and can easily and reliably pull out the wind pipe.

  Next, the embodiment of FIG. 12 includes a lock arm 60 of another mode instead of the lock arms 18, 37, 47, and is formed integrally with the fan case pipe 11 corresponding to the lock arm 60. The configuration of the lock arm accommodating portion 61 is also different from that of the above embodiment. The air discharge pipe 6 fitted into the fan case pipe 11 is the same as that shown in FIG.

  Unlike the lock arm 18 shown in FIG. 3, the lock arm 60 shown in FIG. This point is the same as the lock arms 37 and 47 in FIGS. The lock arm 60 of FIG. 12 is formed in a U shape or a V shape having an elastic folded portion 64 between two arm portions 62 and 63. Then, the lower arm portion 62 that is one arm portion is supported by the lock arm housing portion 61 that is formed integrally with the outer pipe 11, and the distal end portion of the upper arm portion 63 that is the other arm portion is locked. Part 65. Further, the lock arm 60 includes a release operation portion 66 between the elastic folded portion 64 and the lock portion 65.

  The lock arm accommodating portion 61 includes an inner bottom surface portion 67 on which the lower arm portion 62 of the lock arm 60 is placed, and a receiving recess 68 that receives the elastic folded portion 64. The inner bottom surface portion 67 is provided with a stopper 69 that receives the end portion of the lower arm portion 62 and prevents its movement in the axial direction. The receiving recess 68 extends forward in the wind direction along the axis X direction of the fan case pipe 11. The receiving recess 68 is disposed on the front end portion 11 f side of the fan case pipe 11 with respect to the stopper 69. A tool insertion hole 70 is formed in the lock arm accommodating portion 61. The tool insertion hole 70 passes through the lock arm accommodating portion 61 in a horizontal direction perpendicular to the axis X of the fan case pipe 11. The release operation portion 66 of the lock arm 60 protrudes into the tool insertion hole 70 when the fan case pipe 11 is viewed from the left and right sides.

  In the embodiment of FIG. 12, when the rear end 6 r of the air discharge pipe 6 is fitted into the front end portion 11 f of the fan case pipe 11, the engagement protrusion 14 of the air discharge pipe 6 is inclined by the inclined surface 19. It moves toward the inside of the fan case pipe 11 while pushing the lock portion 65 downward. When the discharge pipe 6 is fully inserted, the engagement protrusion 14 passes through the lock portion 65, and the lock portion 65 is engaged with the engagement protrusion 14 by the elasticity of the elastic folding portion 64. 17 is engaged. Thereby, the discharge pipe 6 is fixed to the fan case pipe 11 so as not to come off.

  As already described, the release operation portion 66 of the lock arm 60 protrudes into the tool insertion hole 70 when the fan case pipe 11 is viewed from the left and right sides. The clearance between the upper surface 71 of the release operation part 66 and the inner surface 72 of the tool insertion hole 70 is set smaller than the outer diameter of a rod-like tool such as a screwdriver inserted through the tool insertion hole 70. For this reason, when the rod-shaped tool is inserted into the tool insertion hole 70, the release operation portion 66 is pushed downward by the outer peripheral surface of the rod-shaped tool due to the elasticity of the elastic folding portion 64. Thereby, the lock portion 65 swings downward, and the engagement between the lock portion 65 and the engagement receiving portion 17 is released. For this reason, it becomes possible to remove the air discharge pipe 6 from the fan case pipe 11. When the rod-shaped tool is extracted from the tool insertion hole 70, the lock portion 65 returns to the original locked position due to the elasticity of the elastic folded portion 64.

  Also in the embodiment of FIG. 12, in the state where the engagement state of the lock portion 65 with respect to the engagement protrusion 14 is released by the insertion of the rod-shaped tool into the tool insertion hole 70, Due to elasticity, the bar-shaped tool is held in a released state between the release operation portion 66 and the inner surface 72 of the tool insertion hole 70. For this reason, the operator can remove the hand pipe from the rod-shaped tool and pull out the air discharge pipe 6 with both hands. Therefore, the discharge pipe 6 can be easily and reliably extracted.

  As other embodiments of the present invention, those shown in FIGS. 13 and 14 may be employed. FIG. 13 is a cross-sectional view of a pipe connection structure according to another embodiment of the present invention, and FIG. 14 is a cross-sectional view of a pipe connection structure according to still another embodiment of the present invention.

  The embodiment shown in FIG. 13 includes a lock arm 80 in another mode in place of the lock arms 18, 37, 47, 60, and a lock formed integrally with the fan case pipe 11 corresponding to the lock arm 80. The configuration of the arm accommodating portion 81 is also different from that of the above embodiment. The air discharge pipe 6 fitted into the fan case pipe 11 is the same as that shown in FIG.

  The lock arms 18, 37, 47, 60 already described are formed as separate parts from the fan case pipe 11. Therefore, the lock arms 18, 37, 47, 60 can be attached to and detached from the fan case pipe 11. When the lock arms 18, 37, 47, 60 are damaged, the lock arms 18, 37 are removed. 47, 60 can be exchanged.

  On the other hand, the lock arm 80 in FIG. 13 is integrally formed with the plastic fan case pipe 11 as an outer pipe. The fan case pipe 11 is formed by a combination of left and right semi-cylindrical portions 11L and 11R, similar to that shown in FIG. 2, and the lock arm accommodating portion 81 is also similar to that shown in FIG. It is formed by a combination of left and right box halves 22L and 22R integrally formed at the lower part of the left and right semicylindrical portions 11L and 11R. The fan case pipe 11 in FIG. 13 is in a state in which the right half cylindrical portion 11R located on the front side of the sheet is removed.

  The base portion 82 of the lock arm 80 shown in FIG. 13 is formed integrally with the lock arm accommodating portion 81, and the tip portion that rises vertically serves as the lock portion 83. The lock portion 83 is located on the inner back side of the fan case pipe 11 with respect to the base portion 82. And between the said base part 82 and the said lock part 83, the elastic part 84 and the cancellation | release operation part 85 are provided in an order from the said base part 82 side.

In the embodiment of FIG. 13, when the rear end portion 6 r of the air discharge pipe 6 is fitted into the front end portion 11 f of the fan case pipe 11, the engagement protrusion 14 of the air discharge pipe 6 is inclined by the inclined surface 19. While the lock part 83 is pushed downward, the fan case pipe 11 moves toward the inside. When the discharge pipe 6 is fully inserted, the engagement protrusion 14 passes through the lock portion 83, and the lock portion 83 is engaged with the engagement receiving portion 17 of the engagement protrusion 14 by the elasticity of the elastic portion 84. Engage with. Thereby, the discharge pipe 6 is fixed to the fan case pipe 11 so as not to come off.
A tool insertion hole 86 is formed in the lock arm accommodating portion 81. The tool insertion hole 86 passes through the lock arm accommodating portion 81 in a horizontal direction perpendicular to the axis X of the fan case pipe 11.

  The release operation portion 85 of the lock arm 80 protrudes into the tool insertion hole 86 when the fan case pipe 11 is viewed from the left and right sides. A clearance between the upper surface 87 of the release operation portion 85 and the inner surface 88 of the tool insertion hole 86 is an outer diameter of a rod-like tool such as a screwdriver inserted through the tool insertion hole 86 (see reference numeral 32 in FIG. 7). Set smaller. For this reason, when the rod-shaped tool is inserted into the tool insertion hole 86, the release operation portion 85 is pushed downward by the outer peripheral surface of the rod-shaped tool because the elastic portion 84 is provided. As a result, the lock portion 83 swings downward, and the engagement between the lock portion 83 and the engagement receiving portion 17 is released. When the rod-shaped tool is extracted from the tool insertion hole 86, the lock portion 83 returns to the original position by the elasticity of the elastic portion 84.

  Also in the embodiment of FIG. 13, the elastic portion 84 is elastic in a state where the engagement state of the lock portion 83 with respect to the engagement protrusion 14 is released by the insertion of the rod-like tool into the tool insertion hole 86. Thus, the bar-shaped tool is held in a released state between the release operation portion 85 and the inner surface 88 of the tool insertion hole 86. For this reason, the operator can remove the hand pipe from the rod-shaped tool and pull out the air discharge pipe 6 with both hands. Therefore, the discharge pipe 6 can be easily and reliably extracted.

  By the way, in the embodiment of FIG. 13, the lock arm 80 and the fan case pipe 11 are an integrally molded product made of plastic, which is advantageous in terms of manufacturing cost without requiring assembly steps. If the integrated lock arm) 80 is broken or damaged, it is necessary to replace the fan case pipe 11, which is disadvantageous in terms of repair costs.

  Therefore, the embodiment of FIG. 13 includes means for solving the above problems. That is, an attachment portion 91 for attaching an exchange lock arm 90 (see FIG. 14) instead of the integrated lock arm 80 is formed on the fan case pipe 11 as an outer pipe. The attachment portion 91 is a fitting recess 92 formed in the vicinity of the base portion 82 of the integrated lock arm 80 and a support portion 93 for elastic deformation of the replacement lock arm 90.

  As shown in FIG. 14, when the integrated lock arm 80 is broken, the lock arm accommodating portion 81 is opened, the integrated lock arm 80 is removed, and the replacement lock arm is attached to the mounting portion 91. 90 is attached. In the case where the damaged portion of the integrated lock arm 80 is the lock portion 83, the integrated lock arm 80 is removed from the base portion 82 because it obstructs the mounting of the replacement lock arm 90.

  A fitting portion 94 formed in the base portion of the replacement lock arm 90 is fitted into the fitting recess 92 in an adapted state. The replacement lock arm 90 is supported by the support portion 93 in the state where the fitting portion 94 is fitted in the fitting recess 92 and has the same effect as the integrated lock arm 80. That is, the replacement lock arm 90 has a vertically rising end portion as a lock portion 95, and the elastic portion 96 and the engagement portion 94 are sequentially disposed between the fitting portion 94 and the lock portion 95. A release operation unit 97 is provided. The release operation portion 97 is positioned so as to protrude into the tool insertion hole 86 when the fan case pipe 11 is viewed from the left and right sides. A gap between the upper surface 98 of the release operation portion 97 and the inner surface 88 of the tool insertion hole 86 is set smaller than the outer diameter of the rod-shaped tool inserted through the tool insertion hole 86.

  Therefore, when connecting the air discharge pipe 6 to the fan case pipe 11 and when extracting the air discharge pipe 6 from the fan case pipe 11, the replacement lock arm 90 is connected to the integrated lock arm 80. Has exactly the same effect. Therefore, even if the integrated lock arm 80 is damaged, it is not necessary to replace the fan case pipe 11 and the repair cost can be saved.

  When the replacement lock arm 90 is damaged, the lock arm accommodating portion 81 is opened, the damaged replacement lock arm is removed, and a new replacement lock arm is attached to the attachment portion 91.

  Needless to say, the specific shapes of the mounting portion 91 and the replacement lock arm 90 are not limited to those shown in FIGS. As another embodiment, for example, an exchange lock arm having a shape as shown in FIG. 12 may be used. In this case, it goes without saying that the shape of the mounting portion also corresponds to the shape of the replacement lock arm in FIG.

It is a whole perspective view which shows the use condition of the power blower containing the pipe connection structure which concerns on one Embodiment of this invention. FIG. 2 is an enlarged perspective view of a pipe in FIG. 1 in a disconnected state. It is a side view inside a lock arm accommodating part. FIG. 4 is a cross-sectional view taken along arrow IV-IV in FIG. 2. It is a side view of the connection process of the pipe of FIG. FIG. 3 is a side view of the pipe shown in FIG. It is a side view at the time of pipe removal in the pipe connection structure of FIG. It is a side view of the pipe connection structure which concerns on other embodiment of this invention. It is IX-IX arrow expanded sectional view of FIG. It is a longitudinal cross-sectional enlarged view of FIG. It is sectional drawing of the pipe connection structure which concerns on other embodiment of this invention. It is sectional drawing of the pipe connection structure which concerns on another embodiment of this invention. It is sectional drawing of the pipe connection structure which concerns on other embodiment of this invention. It is sectional drawing of the pipe connection structure which concerns on other embodiment of this invention.

Explanation of symbols

6 Inner pipe (fan pipe)
6r End of inner pipe (rear end of wind pipe)
10 Pipe connection structure 11 Outer pipe (fan case pipe)
11f End of outer pipe (front end of fan case pipe)
DESCRIPTION OF SYMBOLS 15 Wedge-shaped protrusion 16 Guide convex shape 17 Engagement receiving part 18 Lock arm 20 Guide groove 23 Lock part 24 Release operation part 25 Pivot shaft part 26 Elastic return arm part 28 Tool insertion hole 31 Inner surface of tool insertion hole 32 Rod-shaped tool 33 Elasticity Push-back part (back wall part of the guide groove)
34 inclined surface 37 lock arm 39 cantilever support portion 40 lock portion 41 elastic portion 42 release operation portion 44 tool insertion hole 46 inner surface of tool insertion hole 47 lock arm 50 lock portion 51 elastic portion 52 release operation portion 56 engagement receiving portion 57 Tool insertion hole 59 Inner surface of tool insertion hole 60 Lock arm 62 Arm portion 63 Arm portion 64 Elastic folding portion 65 Lock portion 66 Release operation portion 70 Tool insertion hole 72 Inner surface of tool insertion hole 80 Lock arm (integrated lock arm)
83 Locking portion 85 Release operation portion 86 Tool insertion hole 88 Inner surface of tool insertion hole 90 Lock arm (replacement lock arm)
91 Mounting part 95 Locking part 97 Release operation part X Pipe axis

Claims (10)

  A pipe connection structure (10) in which the end (6r) of the inner pipe (6) is fitted into the end (11f) of the outer pipe (11) to prevent the outer pipe (11) from being detached, and the outer periphery of the inner pipe (6) Engagement receiving portions (17, 56) are arranged on the surface, and the outer pipe (11) has tool insertion holes (28, 44, 57, 70, 86) and elastic lock arms (18, 37, 47, 60, 80, 90) and the lock arm (18, 37, 47, 60, 80, 90) is attached to the inner pipe (6) when the pipes (6, 11) are fitted. Lock portions (23, 40, 50, 65, 83, which are pushed and released and engage with the engagement receiving portions (17, 56) by the elasticity to prevent the pipes (6, 11) from being detached) 95) and the tool insertion hole (28, 44, 57, 70, 8) ) Having a release operation part (24, 42, 52, 66, 85, 97) projecting into the tool, and the release operation by the rod-like tool (32) inserted through the tool insertion hole (28, 44, 57, 86). When the portion (24, 42, 52, 66, 85, 97) is pushed, the engagement state of the lock portion (23, 40, 50, 65, 83, 95) with respect to the engagement receiving portion (17, 56) is Pipe connection structure to be released.   By inserting the rod-shaped tool (32) into the tool insertion hole (28, 44, 57, 70, 86), the lock portion (23, 40, 50, 65, 65) with respect to the engagement receiving portion (17, 56). 83, 95) in the released state, the release operation portion (24, 42, 52, 66, 85, etc.) is caused by the elasticity of the lock arm (18, 37, 47, 60, 80, 90). 97) and the inner surface (31, 46, 59, 72, 88) of the tool insertion hole (28, 42, 52, 70, 86), the rod-shaped tool (32) is held in a released state. Item 2. The pipe connection structure according to Item 1.   A wedge-shaped projection (15) that abuts against the inner surface of the outer pipe (11) and eliminates radial play between the pipes (6, 11) in a locking state is provided on the outer peripheral surface of the inner pipe (6). The pipe connection structure according to claim 1 or 2, wherein the pipe connection structure is provided.   Between the two pipes (6, 11), the inner pipe (6) is urged in the anti-fitting direction, and the play in the axis (X) direction between the pipes (6, 11) in the retaining state is fixed. The pipe connection structure according to claim 1, 2 or 3, wherein an elastic push-back portion (33) for eliminating the above is disposed.   A guide groove (20) in the direction of the axis (X) is formed on the inner peripheral surface of the outer pipe (11), and a protrusion (16) that fits the guide groove (20) on the outer peripheral surface of the inner pipe (6). Is formed, the tip of the protrusion (16) in the fitting direction is an inclined surface (34), and the inner wall (33) of the guide groove (20) pushes back the inclined surface (34). The pipe connection structure according to claim 4, which is a part.   The lock arm (18) includes a pivot shaft (25) rotatably supported by the outer pipe (11) between the lock portion (23) and the release operation portion (24). The elastic return arm portion (26) for elastically returning the lock portion (23) to the engagement position with the engagement receiving portion (17) extends from the pivot shaft portion (25). The pipe connection structure as described in any one of thru | or 5.   The lock arm (37, 47) includes a cantilever support portion (39, 49) supported in a cantilever manner on the outer pipe (11) on one end side, and the other end portion on the lock portion (40, 40). 50), and an elastic part (41, 51) and a release operation part (42, 52) are provided between the cantilever support part (39, 49) and the lock part (40, 50). The pipe connection structure according to any one of claims 1 to 5.   The lock arm (60) is formed in a U shape or a V shape having an elastic folded portion (64) between two arm portions (62, 63), and one arm portion (62) is formed on the outer side. The end of the other arm (63) is supported by the pipe (11) and serves as the lock part (65), and the release operation part is provided between the elastic folded part (64) and the lock part (65). The pipe connection structure according to any one of claims 1 to 5, further comprising (66).   The pipe connection structure according to any one of claims 1 to 8, wherein the lock arm (18, 37, 47, 60, 90) is detachable from the outer pipe (11).   The lock arm is an integral lock arm (80) formed integrally with the outer pipe (11), and the outer pipe (11) includes an exchange lock arm (90) instead of the integral lock arm (80). The pipe connection structure according to any one of claims 1 to 8, wherein an attachment portion (91) for attaching the pipe is formed.

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