JP2011001772A - Rammer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a rammer manufacturable at low cost, increased in life by increasing the durability of the sliding portions of an outer guiding and an inner guiding, and improved in operability during the operations and convenience during the transportation by reducing the weight.SOLUTION: The outer and inner guidings are formed of a cylinder part in sliding contact with a mating part and a flange part affixed to a crankcase or a shoe, respectively. The cylinder part which requires wear resistance is made of a structural steel pipe, and the flange part which tends to cause the increase in weight is made of an aluminum casting.

Description

  The present invention relates to a rammer used for tamping the ground in road works and the like, and more particularly to an outer guiding and inner guiding structure that slides on each other to guide a shoe in the vertical direction.

  This type of rammer is used for tamping the ground that has been backfilled or filled in road construction or the like, and examples thereof include those described in Patent Document 1. As will be described below, a prime mover is mounted on the main frame of the rammer, and a crankcase is provided on one side of the main frame. A flange portion of the outer guiding is connected to the lower side of the crankcase, and a cylindrical outer cylinder portion extends downward from the flange portion. An inner guiding cylinder is inserted into the outer cylinder so as to be slidable from below. A shoe for fixing the ground is fixed to the flange provided at the lower end of the inner cylinder. ing. In the crankcase, a crank mechanism is connected to the output shaft of the prime mover via a centrifugal clutch and a reduction gear train, and the lower end of the connecting rod of the crank mechanism is connected to a coil spring accommodated in the inner cylinder portion via a transmission rod. Yes.

  In the rammer constructed in this way, the rotational motion of the output shaft of the prime mover is converted into a reciprocating motion in the vertical direction by the crank mechanism and transmitted to the coil spring through the transmission rod, and the shoe is moved up and down together with the inner cylinder portion. The ground is tamped.

JP 59-206505 A

  As is clear from the above description, since the vertical movement of the shoe is guided by the sliding between the outer cylinder part of the outer guiding and the inner cylinder part of the inner guiding, the outer and inner guidings have wear resistance. On the other hand, since outer and inner guiding occupy a large proportion with respect to the total weight of the runner, weight reduction is also required for the ease of operation of the runner and the convenience of transport.

In general, outer and inner guiding are integrally formed by aluminum casting or FCD (ductile cast iron), but when manufactured by aluminum casting, it is desirable in terms of weight reduction, but the durability of the sliding part is low, and FCD However, there is no problem in terms of durability of the sliding portion, but there is a problem of an increase in weight as compared with an aluminum casting.
In addition, since the outer and inner guidings as a whole have a shape that is long in the vertical direction, a large mold is required for the molding. For this reason, there has also been a problem that the manufacturing cost of the mold increases, which causes the manufacturing cost of the rammer to rise.

  The present invention has been made to solve such problems, and the object of the present invention is to reduce the manufacturing cost and improve the durability of the sliding portion of the outer guiding and the inner guiding. It is an object of the present invention to provide a rammer that can improve the service life and improve the operability during work and the convenience during transportation.

  In order to achieve the above object, according to the first aspect of the present invention, the inner guiding is slidably disposed in the outer guiding fixed to the main body so as to be slidable in the vertical direction, and the driving means mounted on the main body is driven. Outer guiding or inner guiding in a luma that transmits force to the elastic member arranged in the inner guiding through the transmission mechanism and moves the shoe fixed to the lower end together with the inner guiding through the elastic member. At least one of these is divided into a cylinder portion that slides with respect to the other and a flange portion that is fixed to the main body or the shoe.

  Therefore, during the operation of the rammer, the driving force of the driving means is transmitted to the elastic member via the transmission mechanism, and the shoe moves up and down together with the inner guiding to solidify the ground. Up and down movement of the shoe is guided by the sliding of outer guiding and inner guiding, but at least one of them is divided into a cylinder part and a flange part, so each can be made of an optimal material and durable At the same time, the weight can be reduced.

According to a second aspect of the present invention, the cylinder portion is made of a steel material and the flange portion is made of a light metal or a synthetic resin.
Accordingly, since at least one cylinder part of the outer guiding or the inner guiding is made of a steel material rich in wear resistance, the durability of the sliding part is improved and a good guiding function is achieved over a long period of time.

  In addition, the outer guiding and inner guiding flanges are thickened for fixing to the main body and shoe, which causes a significant increase in weight, but on the side divided into the cylinder part and the flange part Since the flange portion is made of light metal or synthetic resin, the entire runner is reduced in weight. On the other hand, when manufacturing the flange part by molding, it can be molded using a small mold compared to molding the entire outer guiding or inner guiding that is long in the vertical direction, thus preventing an increase in manufacturing cost. Is done.

According to a third aspect of the present invention, in the second aspect, the cylinder portion is manufactured by using a steel pipe as a raw material.
Therefore, the outer guiding or inner guiding is divided into a flange part and a cylinder part, so that the cylinder part that slides in the vertical direction becomes a simple cylindrical shape, and it can be manufactured using a ready-made steel pipe in a simple process. It becomes.

According to a fourth aspect of the present invention, in the third aspect of the invention, in the third aspect, the cylinder portion is formed with an expanded portion by flaring at the end of the main body or the shoe side, and the flange portion is formed with a cylinder hole into which the cylinder portion is inserted. In addition, a pressing surface that expands toward the main body or the shoe side is formed in the cylinder hole, and the expanding portion of the cylinder portion is sandwiched between the pressing surface and the main body or the shoe.
Therefore, the flange portion and the cylinder portion are coupled by the expanded portion of the cylinder portion being sandwiched between the pressing surface of the flange portion and the main body or the shoe. As a result, the cylinder hole and the pressing surface can be formed on the flange part side, and the expansion part can be formed on the cylinder part side. Don't be.

As described above, according to the first aspect of the invention, since at least one of the outer guiding and the inner guiding is divided into the cylinder portion and the flange portion, each can be configured with an optimal material, It is possible to realize light weight as well as durability.
According to the second aspect of the invention, in addition to the first aspect, since the cylinder portion is made of a steel material having a high wear resistance, the durability of the sliding portion can be improved and a long life can be realized. Since the flange that causes the weight increase is made of light metal or synthetic resin, the weight can be reduced and the operability during work and the convenience during transportation can be improved. Therefore, the manufacturing cost can be reduced.

According to the third aspect of the invention, in addition to the second aspect, the cylinder portion can be manufactured by a simple process by using a ready-made steel pipe as a raw material.
According to the invention of claim 4, in addition to claim 3, the expansion portion of the cylinder portion is sandwiched between the pressing surface of the flange portion and the main body or the shoe so as to be combined. It can be implemented by simple processing, and since the coupling structure is simple, an increase in weight can be suppressed in advance.

It is sectional drawing which shows the rammer of embodiment. It is the II-II sectional view taken on the line of FIG. 1 which shows the coupling | bond part of the crankcase of a rammer and outer guiding. FIG. 3 is a cross-sectional view taken along the line III-III in FIG. 2, similarly showing a joint portion between the crankcase and the outer guiding. It is the IV-IV sectional view taken on the line of FIG. FIG. 5 is a cross-sectional view taken along the line V-V in FIG. 4, similarly showing a joint portion between the shoe and the inner guiding. It is a fragmentary sectional view corresponding to FIG. 3 which shows another example of the coupling structure using a knock pin. It is a fragmentary sectional view corresponding to FIG. 3 which shows another example of the coupling | bonding structure using the screwing of a screw. It is a fragmentary perspective view which shows another example of the coupling structure using a catch clip.

Hereinafter, an embodiment of a runner embodying the present invention will be described.
FIG. 1 is a cross-sectional view showing a runner according to the present embodiment. As a whole, the runner includes a main body frame 2 (main body) on which the prime mover 1 (driving means) is mounted, a crankcase 3 (main body) provided on one side of the main body frame 2, and an outer extending downward from the crankcase 3. The guiding 4 and the inner guiding 5 and the shoe 6 fixed to the lower end of the inner guiding 5 are configured. Although not shown, an operation bar is attached to one side of the main body frame 2 (left side in FIG. 1). An operator grips the operation bar to drive the ramp and drives the inner guiding 5 and the shoe by driving the prime mover. 6 is moved up and down to tampen the ground.

2 is a cross-sectional view taken along the line II-II of FIG. 1 showing the joint location between the crankcase 3 and the outer guiding 4 of the ramper, and FIG. 3 is a sectional view of the joint portion between the crankcase 3 and the outer guiding 4 in FIG. It is a III-III line sectional view.
Hereinafter, the internal mechanism of the rammer will be described in detail with reference to the drawings. As shown in FIGS. 2 and 3, a flange 8 having a square plate shape is disposed on the lower surface of the crankcase 3, and both members 3, 8 are They are positioned mutually by the inlay 7. Bolt holes 9 (shown at one place in FIG. 3) are formed through the four corners of the flange portion 8, and bolts 10 are inserted into the respective bolt holes 9 from below to be screwed into female threads 11 on the lower surface of the crankcase 3. The flange portion 8 is fastened to the lower surface of the crankcase 3. A circular cylinder hole 12 is provided in the center of the flange portion 8, and a boot flange 13 is formed on the lower surface of the flange portion 8 so as to expand downward around the cylinder hole 12. The inside of the boot flange 13 is a cylinder. The rod hole 14 formed on the lower surface of the hole 12 and the crankcase 3 communicates with the inside of the crankcase 3.

  An upper portion of a cylindrical outer cylinder portion 15 extending in the vertical direction is fitted into the cylinder hole 12 of the flange portion 8 without a gap, and the outer guiding portion 4 is constituted by the flange portion 8 and the outer cylinder portion 15. Has been. At the upper end of the outer cylinder portion 15, an expanded portion 15a that expands in a taper shape upward is formed, and the cylinder hole 12 of the flange portion 8 tapers upward so as to correspond to the expanded portion 15a. A pressing surface 8a that expands in a shape is formed. The pressing surface 8 a of the flange portion 8 receives the fastening force of the bolt 10 and comes into contact with the expanded portion 15 a of the outer cylinder portion 15 from below and sandwiches the expanded portion 15 a with the lower surface of the crankcase 3.

4 is a cross-sectional view taken along the line IV-IV in FIG. 1 showing the joint location between the shoe 6 and the inner guiding 5 of FIG. 4, and FIG. It is V line sectional drawing.
A cylindrical inner cylinder portion 16 extending in the vertical direction is inserted into the outer cylinder portion 15 from below, and both the cylinder portions 15 and 16 can slide in the vertical direction. A cylinder hole 18 penetrating in the center of the flange portion 17 is fitted into the lower portion of the inner cylinder portion 16 without any gap, and the inner guiding 5 is configured by the inner cylinder portion 16 and the flange portion 17. A boot flange 19 is formed on the upper surface of the flange portion 17 so as to expand upward with the cylinder hole 18 as a center. The boot flange 19 and the boot flange 13 on the outer guiding 4 side include a boot 20 having a cylindrical bellows shape. Connected through. As a result, the outer and inner cylinder portions 15 and 16 are accommodated in the space formed by the boot flanges 13 and 19 and the boot 20 and are protected from dust and water in the construction environment.

The fixing base 6a of the shoe 6 is located below the flange portion 17 of the inner guiding 5. The female base 21 formed at the four corners of the lower surface of the flange portion 17 (shown at one place in FIG. 5) has a fixing base 6a. A bolt 23 is screwed from below through a bolt hole 22 penetrating into the flange portion 17, and the shoe 6 is fastened together with the fixed base 6 a to the flange portion 17.
Basically, the relationship between the inner cylinder portion 16 and the flange portion 17 has the same structure that is upside down with respect to the relationship between the outer cylinder portion 15 and the flange portion 8 described above. That is, the lower end of the inner cylinder portion 16 is formed with an expanded portion 16a that expands downward in a tapered shape, and the cylinder hole 18 of the flange portion 17 is directed downward so as to correspond to the expanded portion 16a. Thus, a pressing surface 17a that expands in a tapered shape is formed. The pressing surface 17a of the cylinder hole 18 receives the fastening force of the bolt 23 and comes into contact with the expanded portion 16a of the inner cylinder portion 16 from above, and sandwiches the expanded portion 16a with the upper surface of the fixed base 6a.

  On the other hand, as shown in FIG. 1, in the crankcase 3, a drive gear 26a is connected to the output shaft 1a of the prime mover 1 via a centrifugal clutch 25, and a driven gear 26b is meshed with the drive gear 26a so that a reduction gear train. 26 (transmission mechanism) is configured. The upper end of the connecting rod 27 is slidably connected to the eccentric position of the driven gear 26 a by a pin 28, and the lower end of the connecting rod 27 is swayed by a pin 30 to a slider 29 slidably disposed in the outer cylinder portion 15. The crank mechanism 31 (transmission mechanism) is configured so as to be movable. An upper end of a transmission rod 32 is connected to the slider 29, and a lower portion of the transmission rod 32 is inserted into the inner cylinder portion 16 through the outer cylinder portion 15. A coil spring 33 is accommodated in the inner cylinder portion 16 and is prevented from detaching from the stopper 34. A retainer 35 fixed to the lower end of the transmission rod 32 is fitted between the windings in the middle in the vertical direction of the coil spring 33. It is.

  In this embodiment, the flange portions 8 and 17 of the outer and inner guidings 4 and 5 are made of an aluminum casting, and the cylinder portions 15 and 16 are made of a structural steel pipe (STK). More specifically, the flange portions 8 and 17 are cast using aluminum having a corresponding shape as a material. In addition, the cylinder parts 15 and 16 are the inner and outer diameters of the desired cylinder parts 15 and 16 (inner diameter and inner cylinder part for the outer cylinder part 15) from the structural steel pipe standards defined by JIS (Japanese Industrial Standards). After selecting a material that matches the outer diameter of 16, the length of each material is cut according to the target cylinders 15 and 16, and the upper or lower opening is further expanded by pressing. The expanded portions 15a and 16a are formed by so-called flare processing.

  If the inner diameter of the outer cylinder section 15 and the outer diameter of the inner cylinder section 16 that are slidable with each other do not exist within the standard of the structural steel pipe, one of them is cut to the other diameter. You may make it correspond. In addition, JIS structural steel pipes are classified into forged steel pipes and seamless steel pipes, etc., depending on the manufacturing method, and are classified into hot finishing and cold finishing, etc. depending on the finishing method. May be.

  Such a divided structure of the outer and inner guidings 4 and 5 aims to achieve both improvement in wear resistance and weight reduction of the sliding portion. That is, the inventor of the present invention requires that the wear resistance is required for the outer and inner guiding members 4 and 5 in the cylinder portions 15 and 16 that slide relative to each other. In other words, the flange portions 8 and 17 do not contribute significantly to the weight reduction of the guiding members 4 and 5 even if the cylinder portions 15 and 16 are lightened, and the wear resistance of the flange portions 8 and 17 is improved. However, in this embodiment, the outer and inner guidings 4 and 5 are divided into configurations in these parts, and the optimum physical properties required for each part are provided. The problem is solved by setting appropriate materials. Therefore, hereinafter, the operational effects obtained by the divided configuration of the outer and inner cylinder portions 4 and 5 will be described along with the operation status of the runner.

  During operation of the runner, the rotation of the output shaft 1a of the prime mover 1 is input to the centrifugal clutch 25, and when the rotational speed of the prime mover 1 is increased and the centrifugal clutch 25 is connected according to the operation of the operator, the output shaft The rotational motion of 1a is converted into a reciprocating motion in the vertical direction via the connecting rod 27 of the crank mechanism 31 after being decelerated by the reduction gear train 26 and transmitted to the slider 29. The retainer 35 moves up and down through the transmission rod 32 together with the slider 29, and the up-and-down movement is transmitted to the inner cylinder part 16 while elastically deforming the coil spring 33, and the shoe 6 moves up and down together with the inner cylinder part 16 and the ground. The tamping is done.

  The vertical movement of the shoe 6 at this time is guided by the sliding of the outer and inner cylinder portions 15 and 16, and the inner peripheral surface of the outer cylinder portion 15 and the outer peripheral surface of the inner cylinder portion 16 are always in contact with each other during the operation of the runner. Continue to slide. In the present embodiment, the outer and inner cylinder parts 15 and 16 are made of structural steel pipes with high wear resistance, so that the durability of each sliding part is improved and a good guiding function is achieved over a long period of time. As a result, the life of the luma can be extended.

  Further, since the flange portions 8 and 17 of the outer and inner guidings 4 and 5 are formed thick for fastening with the bolts 10 and 23 to the crankcase 3 and the shoe 6, the outer and inner guiding 4 In this embodiment, these flange portions 8 and 17 are much lighter than, for example, FCD (specific gravity about 7.2) or structural steel pipe (specific gravity about 7.8). Since it is made of a simple aluminum casting (specific gravity of about 2.7), the overall weight of the outer and inner guidings 4 and 5 is greatly reduced. As a result, the entire runner can be significantly reduced in weight, and both the operability during work of the runner and the convenience during transportation can be improved.

  Furthermore, by dividing the outer and inner guidings 4 and 5, the cylinder portions 15 and 16 that slide in the vertical direction can be formed into a simple cylindrical shape. Therefore, in the present embodiment, a ready-made structural steel pipe is used as a material in view of the shapes of the cylinder portions 15 and 16. For this reason, compared with the case where the cylinder parts 15 and 16 are manufactured by cutting from a round bar, for example, the cylinder parts 15 and 16 can be manufactured by a much simpler process, and the manufacturing cost of the rammer is reduced. Can do.

  On the other hand, the shocking reaction force when the ground is squeezed by the shoe 6 acts on the outer and inner guidings 4 and 5, particularly in the vicinity of the flange portions 8 and 17 which are the base ends of the both guidings 4 and 5. Because of the concentration, high bonding strength is required between the flange portions 8 and 17 and the cylinder portions 15 and 16. On the other hand, conventional means such as welding cannot be applied to the flange portions 8 and 17 and the cylinder portions 15 and 16 which are different materials, and if a complicated joint structure is adopted as a countermeasure, the weight of the flange portions 8 and 17 due to aluminization. It may be a factor that impairs mitigation.

  Therefore, in the present embodiment, the upper or lower portions of the cylinder portions 15 and 16 are fitted in the cylinder holes 12 and 18 of the flange portions 8 and 17 without any gap to restrict the position in the horizontal direction. By sandwiching the formed expanded portions 15a and 16a between the pressing surfaces 8a and 17a of the flange portions 8 and 17 and the lower surface of the crankcase 3 or the fixed base 6a of the shoe 6 by the fastening force of the bolts 10 and 23, By restricting the position in the horizontal direction and the vertical direction, the flange portions 8 and 17 and the cylinder portions 15 and 16 are coupled.

  As a result, the cylinder holes 12 and 18 and the pressing surfaces 8a and 17a are formed on the flange portions 8 and 17 side, and the expanded portions 15a and 16a are formed on the cylinder portions 15 and 16 side. In addition, since the coupling structure is simple, it does not increase the weight. When assembling the rammers, the cylinder portions 15 and 16 are inserted into the cylinder holes 12 and 18 of the flange portions 8 and 17 so that the flange portions 8 and 17 are connected to the crankcase 3 and the shoe 6 on the other side with bolts 10 and 16. Since the coupling between the flange portions 8 and 17 and the cylinder portions 15 and 16 is completed by simply fastening at 23, there is an advantage that the assembling work can be simplified.

  It is not always necessary to fit the cylinder portions 15 and 16 into the cylinder holes 12 and 18 of the flange portions 8 and 17, for example, when the expanded portions 15a and 16a have sufficient strength, the expanded portion 15a. The flange portions 8 and 17 and the cylinder portions 15 and 16 may be coupled only by clamping to the 16a. However, in order to more firmly join both members 8, 17, 15, 16, it is desirable to fit the cylinder parts 15, 16 into the cylinder holes 12, 18.

  Further, as apparent from FIG. 5, on the inner guiding 5 side, a protrusion 36 having a square section is formed on the fixed base 6 a of the shoe 6 so as to form an annular shape corresponding to the expanded portion 16 a of the inner cylinder portion 16. When the bolt 23 is fastened, not only the tip of the expanded portion 16a of the inner cylinder portion 16 abuts on the fixed base 6a but also the lower surface of the expanded portion 16a abuts on the upper portion of the protrusion 36. . For this reason, the expansion part 16a can be clamped still more firmly between the pressing surface 17a of the flange part 17 and the fixed base 6a. The cross-sectional shape of the ridge 36 is not limited to the square shape shown in FIG. 5, but is formed in a triangular shape corresponding to the taper of the widened portion 16a, for example, so that the entire lower surface of the widened portion 16a abuts. You may do it. A similar protrusion 36 may be formed on the outer guiding 4 side.

In addition to the above, by providing the outer and inner guidings 4 and 5 in a divided configuration, various excellent effects described below can be obtained.
First, since the flange portions 8 and 17 can be used in common and the specifications of the cylinder portions 15 and 16 can be changed, it is possible to deal with a wide variety of rammers at low cost. For example, specifications using inexpensive materials for the cylinder portions 15 and 16 for cost reduction, specifications using materials with particularly high wear resistance for the cylinder portions 15 and 16 for further improvement of durability, and wear resistance In order to reduce the weight as much as possible while ensuring the performance, when producing the rammers with the specifications using relatively low specific gravity material for the cylinder parts 15 and 16, respectively, the common flange parts 8 and 17 should be used throughout each specification. As a result, it is possible to realize a wide variety of Ranma at low cost. This point applies not only to the material of the cylinder parts 15 and 16 but also to the shape thereof, and can be inexpensively adapted to a variety of rammers having different shapes of the cylinder parts 15 and 16.

  Further, even if a structural steel pipe having high wear resistance is used, the cylinder portions 15 and 16 may be worn out, and the outer or inner guidings 4 and 5 may be damaged during the work. In such a case, in this embodiment in which the guidings 4 and 5 are divided into the flange portions 8 and 17 and the cylinder portions 15 and 16, only the damaged side can be replaced to repair the rammer. Compared to the prior art that requires a complete replacement, the repair cost can be greatly reduced.

  In addition, as is well known, aluminum has a feature that it is harder to corrode than FCD and the like, and therefore, the flange portions 8 and 17 made of cast aluminum can be made uncoated. Therefore, by omitting the coating treatment of the flange portions 8 and 17, the environmental load during production can be reduced by reducing the VOC (volatile organic compound), and corrosion due to paint peeling as in the prior art made by FCD is obviated. Can be prevented.

On the other hand, when the flange portions 8 and 17 are cast with an aluminum casting as in the present embodiment, a mold is required, but compared with the conventional technology in which the outer and inner guidings 4 and 5 are molded as a whole in the vertical direction. The flange portions 8 and 17 can be cast using a very small mold, and this factor also contributes to a reduction in manufacturing cost.
This is the end of the description of the present embodiment, but the present invention is not limited to this and can be variously modified. For example, in the above embodiment, the outer and inner guidings 4 and 5 are both divided into the flange portions 8 and 17 and the cylinder portions 15 and 16, but only one of them is divided and the other is the prior art. Similarly, it may be integrally formed with an aluminum casting or FCD.

  In the above embodiment, the flange portions 8 and 17 are made of an aluminum casting, and the cylinder portions 15 and 16 are made of a structural steel pipe. However, as long as the physical properties required for each part are satisfied, It is not limited to. Specifically, with respect to the flange portions 8 and 17 that are particularly required to be lighter, a light metal having a low specific gravity, such as magnesium (specific gravity of about 1.7) or titanium (specific gravity of about 4.5) may be used among non-ferrous metals. Alternatively, injection molding may be performed with a synthetic resin material, for example, engineering plastic such as polyamide (PA) or polycarbonate (PC). On the other hand, regarding the cylinder parts 15 and 16 that require particularly wear resistance, iron and iron-based alloys, that is, steel materials may be used, for example, instead of structural steel pipes. The cylinder parts 15 and 16 may be made of steel pipe. Further, the cylinder portions 15 and 16 may be cast by a heat-treated casting such as FCD or FCAD (Austempered Spheroidal Graphite Cast Iron) without using a ready-made steel pipe, or a round bar such as carbon steel or tool steel. Alternatively, it may be manufactured by cutting. Even in these cases, the same effect as the embodiment can be obtained.

  On the other hand, in the above embodiment, the cylinder portion 15 is formed between the pressing surfaces 8a, 17a of the flange portions 8, 17 and the lower surface of the crankcase 3 or the fixed base 6a of the shoe 6 by using the fastening force of the bolts 10, 23. , 16 of the expanded portions 15a, 16a are sandwiched, but this coupling structure can be variously changed, and another example will be described below. Although these other examples are directed to the outer guiding 4 side, a similar coupling structure can be applied to the inner guiding 5 side.

  FIG. 6 is a partial cross-sectional view corresponding to FIG. 3 showing another example of a coupling structure using knock pins. As in the above embodiment, the crankcase 3 and the flange portion 8 are positioned by the inlay 7, and a knock hole 41 penetrating the crankcase 3 and the flange portion 8 from the side is formed at the location of the inlay 7. The knock pin 42 is press-fitted into the knock hole 41. As a result, the crankcase 3 and the flange portion 8 are coupled by the knock pin 42, whereby the expanded portion 15 a of the outer cylinder portion 15 is sandwiched between the pressing surface 8 a of the cylinder hole 12 and the lower surface of the crankcase 3. .

  FIG. 7 is a partial cross-sectional view corresponding to FIG. 3 showing another example of a coupling structure using screw threading. A male screw 51 is formed on the outer periphery of the outer cylinder portion 15 below the expanded portion 15a. The male screw 51 is screwed with a female screw 52 formed on the inner periphery of the cylinder hole 12 of the flange portion 8. As a result, in this case, the outer cylinder portion 15 is not only sandwiched by the expanded portion 15a, but is also coupled to the flange portion 8 by screwing of the male screw 51 and the female screw 52.

  FIG. 8 is a partial perspective view showing another example of a coupling structure using a catch clip. Catch clips 61 are attached to the two opposite sides of the crankcase 3, and hooks 62 are attached to the two opposite sides of the flange portion 8 (only one of them is shown). Each catch clip 61 is hooked to a corresponding hook 62, whereby the flange portion 8 is fastened to the crankcase 3, and although not shown, the expanded portion 15 a of the outer cylinder portion 15 is sandwiched in the flange portion 8. ing. Note that if the catch clip 61 alone is unstable in the horizontal direction, an inlay may be formed between the crankcase 3 and the flange portion 8.

1 prime mover (drive means)
2 Body frame (body)
3 Crankcase (main body)
4 Outer guiding 5 Inner guiding 6 Shoe 8, 17 Flange portion 8a, 17a Press surface 12, 18 Cylinder hole 15 Outer cylinder portion 15a, 16a Expanding portion 16 Inner cylinder portion 26 Reduction gear train (transmission mechanism)
31 Crank mechanism (transmission mechanism)
32 Coil spring (elastic member)

Claims (4)

The inner guiding is slidably arranged in the outer guiding fixed to the main body, and the driving force of the driving means mounted on the main body is arranged in the inner guiding through the transmission mechanism. In the rammer that transmits to the elastic member and moves the shoe fixed to the lower end together with the inner guiding through the elastic member,
At least one of the outer guiding or the inner guiding is divided into a cylinder portion that slides with respect to the other and a flange portion that is fixed to the main body or the shoe. .   The runner according to claim 1, wherein the cylinder part is made of a steel material and the flange part is made of a light metal or a synthetic resin.   3. The rammer according to claim 2, wherein the cylinder part is made of a steel pipe. The cylinder part has a widened part formed by flaring at the end of the main body or the shoe side,
The flange portion is formed with a cylinder hole into which the cylinder portion is inserted, and a pressing surface is formed in the cylinder hole so as to expand toward the main body or the shoe, and the main surface or the shoe is formed by the pressing surface. 4. The rammer according to claim 3, wherein an expanded portion of the cylinder portion is sandwiched between the two.

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