JP2018130740A - Crankshaft and press machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a crankshaft and a press machine which have durability higher than conventional ones.SOLUTION: In a crankshaft 30, a crank pin 33 is stretched between first and second crank webs 31 and 32. One end of the crank pin 33 is fitted into a pin hole 41 formed in the first crank web 31. A center hole 40 which partially overlaps the pin hole 41 and into which a bearing 24 is fitted is formed in a central section of the first crank web 31. A circular arc groove section 43 is caved and formed on an outer peripheral surface at the one end of the crank pin 33 conforming to the shape of a portion projecting to the pin hole 41 side in the bearing 24.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a crankshaft in which a crankpin is interposed between a pair of crank webs, and a press machine including such a crankshaft.

  Conventionally, as this type of crankshaft, in order to pass the crankpin through the through hole of the connecting rod, the crankpin is fitted into a pin hole formed in the crank web so that the crank web and the crank pin can be separated. (For example, see Patent Documents 1 and 2).

Utility Model Registration Gazette No. 2570281 (FIGS. 1 and 2) Japanese Patent No. 5138426 (FIGS. 1 and 5)

  In the case where the crankpin and the crank web are separated as in the above-described conventional crankshaft, durability may be a problem as compared with the case where the crankpin and the crank web are integrated.

  The present invention has been made in view of the above circumstances, and an object thereof is to provide a crankshaft and a press machine having higher durability than conventional ones.

  In order to achieve the above object, the invention of claim 1 is characterized in that one end portion of a crank pin inserted between the first and second crank webs has a pin hole formed in the first crank web. A center shaft of the first crank web that is partially overlapped with the pin hole and into which the bearing is fitted, and from the center hole of the bearing. In accordance with the shape of the portion protruding to the pin hole side, the crankshaft is provided with an arcuate groove portion that is recessed and formed on the outer peripheral surface of the one end portion of the crankpin.

  According to a second aspect of the present invention, the crank pin is formed integrally with the second crank web, and the second crank web is provided with a torque transmission portion to which a drive source or a load is connected. 1. The crankshaft according to 1.

  The invention of claim 3 is a press machine comprising the crankshaft according to claim 1 or 2 and a ram connected to the crankshaft via a connecting rod.

  The crankshaft according to claim 1 has a structure in which one end of the crankpin is fitted into a pin hole formed in the first crank web. Thereby, a crankpin can be rotatably connected with the one end part of a connecting rod in the state which isolate | separated the 1st crank web and the crankpin. Here, the bearing that rotatably supports the crankshaft is normally fitted to a crank journal that protrudes from the crank web, but in the present invention, the bearing is fitted to the center hole of the first crank web, It arrange | positions in the position which overlaps with the one end part of a crankpin in radial direction. That is, according to the present invention, a portion where the crankshaft receives a load from the connecting rod (crank pin) and a portion where the crankshaft is rotatably supported (portion where the bearing fits) are brought closer to the normal structure. be able to. Thereby, the bending stress which a crankshaft receives is suppressed, durability is improved, and the crankshaft can be made compact in the axial direction. Moreover, by providing the arc groove on the crankpin, the bearing can be enlarged, and the durability is improved in this respect as well.

  As in the crankshaft of the second aspect, it is preferable that the torque transmitting portion is disposed on the second crank web in which the crank pin is integrally formed.

  The press machine according to claim 3 is provided with the crankshaft of the present invention, so that durability can be improved.

Side sectional view of the press according to the first embodiment of the present invention. Sectional drawing of the press machine in the AA cut surface of FIG. Crankshaft perspective view Side sectional view of a press according to the second embodiment.

[First Embodiment]
Hereinafter, an embodiment of the present invention will be described with reference to FIGS. FIG. 1 shows a main part of a press machine 10 according to the present invention. The press machine 10 includes a support plate 11 standing upright, and a slide rail 12 extending in the vertical direction is attached to a front side surface 11A of the support plate 11. A ram 13 is slidably attached to the slide rail 12, and one or more punches 13 </ b> P are suspended from the ram 13. A die holder (not shown) is provided below the ram 13, and a die corresponding to the punch 13P is attached to the upper surface of the die holder. The die holder is fixed to the support plate 11. As the ram 13 moves up and down, the punch 13P and the die cooperate to bend or cut the workpiece from the sheet metal.

  A support box 15 is provided at the upper end of the support plate 11. The support box 15 is inserted between a pair of support protrusion walls 16 and 16 that protrude from the front side surface 11A of the support plate 11 and face each other in the horizontal direction, and between the front ends of the support protrusion walls 16 and 16 (see FIG. 2). The support opposing wall 17 is opposed to the support plate 11, and the upper and lower surfaces are open. The support facing wall 17 is positioned with respect to the support projecting walls 16 and 16 by a positioning pin (not shown), and is detachably fixed to the support projecting walls 16 and 16 with a bolt (not shown).

  The crankshaft 30 according to the present invention is passed between the support facing wall 17 and the support plate 11, and the crankshaft 30 and the ram 13 are connected by the connecting rod 20. Further, the crankshaft 30 is rotationally driven by the drive source 22, whereby the ram 13 moves up and down.

  Specifically, a through hole 18 is formed in the support plate 11 at a position facing the support facing wall 17. A support sleeve 19 is fitted and fixed to the through hole 18 from the front surface 11A side of the support plate 11, and a part of the support sleeve 19 protrudes to the support opposing wall 17 side. The drive source 22 is formed by connecting a speed reducer to one end of the motor. And the one end surface by the side of the reduction gear of the drive source 22 is fixed to the back side surface 19B of the support sleeve 19, and the output shaft 22J of the drive source 22 is arrange | positioned in the center in the center hole 19C. .

  The crankshaft 30 includes first and second crank webs 31 and 32 on both sides of a crankpin 33 to which the connecting rod 20 is connected. As shown in FIG. 3 (A), the first and second crank webs 31 and 32 have a disk shape arranged coaxially with each other.

  A crank journal 34 (corresponding to a “torque transmitting portion” in the present invention) protrudes from the center of the second crank web 32 on the side opposite to the first crank web 31. As shown in FIG. 1, the crank journal 34 is positioned in the center hole 19C of the support sleeve 19, and the bearing 23 is fitted between the crank journal 34 and the inner peripheral surface of the center hole 19C. Further, a connecting hole 34A is formed at the center of the crank journal 34, and an output shaft 22J of the drive source 22 is fitted into the connecting hole 34A and is key-coupled. The bearing 23 may be, for example, a bearing or a metal bearing, and the same applies to the other bearings 21A, 21B, and 24 described later.

  A center hole 40 is formed at the center of the first crank web 31. Further, a through hole 17 </ b> A having a smaller diameter than the center hole 40 is formed on the support facing wall 17 on the same axis as the center hole 40. Further, a support shaft 29 is inserted into the through hole 17 </ b> A from the opposite side of the first crank web 31, and a flange 29 </ b> F on the base end side of the support shaft 29 is fixed to the support facing wall 17. The tip of the support shaft 29 is received in the center hole 40, and the bearing 24 is fitted between the outer peripheral surface of the support shaft 29 and the inner peripheral surface of the center hole 40.

  The center hole 40 has a stepped diameter from the position close to the end on the second crank web 32 side to the second crank web 32 side in a stepped shape, and is stepped on the position close to the end on the second crank web 32 side. 40D. Then, one end surface of the bearing 24 is abutted against the step surface 40D. Specifically, when the bearing 24 is a bearing, the outer is fitted into the center hole 40 and abutted against the stepped surface 40D. When the bearing 24 is a metal bearing, a sliding metal is used. A sleeve on the inner surface is fitted into the center hole 40 and abuts against the step surface 40D. The bearing 24 slightly protrudes from the surface of the first crank web 31 opposite to the second crank web 32 (hereinafter referred to as “outer surface 31G”). The bearing 24 is prevented from coming off from the center hole 40 by a bearing retainer 49 disposed between the outer surface 31G of the first crank web 31 and the support facing wall 17.

  As described above, the crankshaft 30 is rotatably supported by the bearings 23 and 24 at both ends.

  As shown in FIG. 1, the connecting rod 20 has a strip shape extending in the vertical direction, and through holes 20 </ b> A and 20 </ b> B are provided at both the upper and lower ends of the connecting rod 20. It penetrates in the rotation axis direction H1 of the shaft 30). Further, bearings 21A and 21B are fitted in the through holes 20A and 20B. Further, the collar 33Y penetrates the inside of the bearing 21A at the upper end portion of the connecting rod 20, and the collar 33Y protrudes outward from both ends of the bearing 21A.

  In order to connect the lower end portion of the connecting rod 20 to the ram 13, the ram 13 is provided with a pair of opposing walls 13A and 13B that oppose each other in the rotation axis direction H1 of the crankshaft 30. The pin hole 13C penetrates. And the lower end part of the connecting rod 20 is arrange | positioned between opposing wall 13A, 13B, and the connection pin 28 has penetrated the inside of the bearing 21B of the pin hole 13C and the connecting rod 20. FIG. Thereby, the lower end part of the connecting rod 20 is connected with the ram 13 so that rotation is possible.

  On the other hand, in order to connect the upper end portion of the connecting rod 20 to the crankshaft 30, the crankshaft 30 can be separated between the crankpin 33 and the first crank web 31 as shown in FIG. ing. That is, the crankshaft 30 is formed by combining two parts of the first crank web 31 and a main body portion 30 </ b> A integrally provided with a second crank web 32, a crank pin 33, and a crank journal 34.

  The above-described center hole 40 is formed through the center of the first crank web 31, and a pin hole 41 is formed through the position eccentric from the center of the first crank web 31. Then, the crank pin 33 of the main body 30A is passed through the collar 33Y on the upper end side of the connecting rod 20 in a state where the main body 30A and the first crank web 31 are separated. And the front-end | tip part of the crankpin 33 is fitted in the pin hole 41 of the 1st crank web 31, and the main-body part 30A and the 1st crank web 31 are united. In this way, the upper end portion of the connecting rod 20 is rotatably connected to the crankshaft 30.

  Now, the center hole 40 and the pin hole 41 of the first crank web 31 partially overlap each other. As shown in FIG. 2, the bearing 24 fitted in the center hole 40 projects to the pin hole 41 side. On the other hand, on the outer peripheral surface of the distal end portion of the crank pin 33, an arc groove portion 43 is formed in a recessed manner in accordance with the shape of the portion of the bearing 24 that projects to the pin hole 41 side. As shown in FIG. 3A, when the crank pin 33 is fitted into the pin hole 41, the concave arc surface 43A of the arc groove 43 and the inner peripheral surface 40A of the center hole 40 are flush with each other. One cylindrical surface.

  When the crank pin 33 is fitted into the pin hole 41, the collar 33 </ b> Y is sandwiched between the first and second crank webs 31 and 32 and the tip surface of the crank pin 33 is slightly retracted into the pin hole 41. Placed in position. Further, a screw portion 33N is formed at the center of the front end surface of the crank pin 33, and a bolt passed through the through hole 48A of the retaining plate 48 superimposed on the outer surface 31G of the first crank web 31 is fastened to the screw portion 33N. . Thereby, the collar 33Y is sandwiched between the first and second crank webs 31 and 32, and the first crank web 31 is separated from the second crank web 32 by the axial length of the collar 33Y. Is positioned.

  As shown in FIG. 3A, the retaining plate 48 has a shape obtained by cutting a portion overlapping with the center hole 40 from a disk larger than the pin hole 41 and concentric with the pin hole 41, and has a through hole at the center. 48A is provided. As shown in FIG. 3B, the end surface of the arc groove 43 is a step surface 43D perpendicular to the axial direction of the crankpin 33, and the step surface 43D is the end surface of the bearing 24 in the center hole 40. It opposes through a gap. Further, the bearing 24 is fitted into the support shaft 29 and is prevented from coming off into the center hole 40 by a bearing retainer 49 sandwiched between the support facing wall 17 and the first crank web 31. The bearing retainer 49 has a shape obtained by cutting a portion overlapping the retaining plate 48 from an annular plate that overlaps the opening edge of the center hole 40 and projects toward the center hole 40.

  The positioning structure of the bearings 21A, 21B, and 23 other than the bearing 24 in the center hole 40 is well known and will not be described.

  The description regarding the structure of the crankshaft 30 and the press 10 of this embodiment is above. Next, functions and effects of the crankshaft 30 and the press 10 will be described.

  The operation of assembling the press machine 10 is performed as follows. With respect to the press 10 shown in FIG. 1, the upper end portion of the connecting rod 20 is connected to the crankpin 33 before the supporting opposing wall 17 and the first crank web 31 are assembled, and then the lower end of the connecting rod 20 is connected. The part is connected to the ram 13. On the other hand, with respect to the first crank web 31, the bearing 24 is fitted in the center hole 40 and is prevented from coming off by the bearing retainer 49. Then, the crank pin 33 is fitted into the pin hole 41 of the first crank web 31, and the retaining plate 48 is screwed to the crank pin 33. Then, due to the engagement between the bearing 24 in the center hole 40 of the first crank web 31 and the arc groove 43 of the crank pin 33, the first crank web 31 is prevented from rotating with respect to the crank pin 33, and the center hole 40 and the crank journal 34 are held in a centered state. Further, the first crank web 31 is fixed to the main body 30A of the crankshaft 30 via the bearing 24 in the rotation axis direction H1. As a result, it is possible to easily perform the work of assembling the support facing wall 17 to the support protruding wall 16 and fitting the support shaft 29 into the bearing 24 of the first crank web 31 thereafter. Then, the support shaft 29 is fixed to the support facing wall 17 and the assembly to the press machine 10 is completed.

  By the way, a general crankshaft is provided with crank journals at both ends, and both crank journals are rotatably supported by bearings. On the other hand, the crankshaft 30 of the present embodiment is disposed at a position where the bearing 24 is provided in the center hole 40 of the first crank web 31 and overlaps one end portion of the crankpin 33 in the radial direction. In other words, a portion of the crankshaft 30 that receives a load from the connecting rod 20 (crank pin 33) and a portion that is rotatably supported (portion where the bearing 24 is fitted) are closer to each other than a general crankshaft. Yes. Thereby, the bending stress which the crankshaft 30 receives is suppressed, durability is improved, and the crankshaft 30 can be configured to be compact in the axial direction. The press machine 10 also has improved durability and becomes compact. In addition, the provision of the arc groove 43 in the crank pin 33 makes it possible to increase the size of the bearing 24, and this also improves the durability. Furthermore, as described above, in the process of assembling the crankshaft 30 to the press machine 10, the first crank web 31 is prevented from rotating with respect to the main body 30A, so that the assembling work can be easily performed.

  The main body 30A of the crankshaft 30 can be manufactured as follows. That is, for example, a columnar base material is prepared and attached to a lathe, and the crank journal 34 and the connecting hole 34A are processed at the center of one end surface of the base material. Next, a first adapter having a fitting hole is prepared, and a crank journal 34 as a base material is fitted into the fitting hole to prevent rotation. Next, the first adapter is attached to the lathe and rotated together with the base material, and the first circular hole is processed in the central portion of the other end surface of the base material with reference to the crank journal 34. Next, the base material is removed from the first adapter, a second adapter having a fitting hole is prepared at an eccentric position of the outer circular member, and the crank journal 34 of the base material is fitted into the fitting hole. And stop it. Then, the second adapter is attached to the lathe and rotated together with the base material to cut out the crank pin 33 from the base material, and the second crank web 32 is processed. Thereby, the main body 30A of the crankshaft 30 can be processed from the base material, and a part of the first circular hole is left on the outer peripheral surface of the crankpin 33 as the arc surface 43A of the arc groove portion 43.

[Second Embodiment]
The crankshaft 30V of the press machine 10V of the present embodiment is shown in FIG. The so-called double crank having two crank pins 33 and two connecting rods 20 is assembled in order. The first main body 50 has the same structure as the main body 30A of the first embodiment except that the crank pin 33 does not have the arc groove 43. Further, the intermediate crank web 51 has a center hole 40 and a pin hole 41, which are partially overlapped, like the first crank web 31 of the first embodiment. And the crank pin 33 of the 1st main-body part 50 fits in the pin hole 41, and a part of crank pin 33 has protruded to the center hole 40 side.

  The second main body 52 is different from the main body 30A of the first embodiment only in the shape of the crank journal 34. That is, the crank journal 34 is rotatably supported by the bearing 26 through a support facing wall 17 </ b> V provided at the support box 15 at the base end portion. Further, the tip of the crank journal 34 is fitted in the center hole 40 of the intermediate crank web 51. An arc groove 43V is formed on the outer peripheral surface of the tip of the crank journal 34, and the crank pin 33 of the first main body 50 is engaged with the arc groove 43V, whereby the second main body 52 and the intermediate crank are engaged. The web 51 is connected to be integrally rotatable. Further, the end crank web 53 has the same shape as the first crank web 31 of the first embodiment.

[Other Embodiments]
The present invention is not limited to the above-described embodiment. For example, the embodiments described below are also included in the technical scope of the present invention, and various other than the following can be made without departing from the scope of the invention. It can be changed and implemented.

(1) In the above embodiment, the crank pin 33 is formed integrally with the second crank web 32. However, a pin hole is also provided in the second crank web 32, and the crank pin 33 is fitted into the pin hole. It is good also as a structure which stopped by combining.

(2) In the above-described embodiment, the present invention is applied to the crankshaft 30 that applies power to the connecting rod 20, but the present invention may be applied to a crankshaft that receives power from the connecting rod side.

(3) The crankshaft 30 of the present invention is not limited to the one provided in the press machine 10, and may be used for a spring machine, for example.

DESCRIPTION OF SYMBOLS 10 Press machine 13 Ram 24 Bearing 30, 30V Crankshaft 31 1st crank web 32 2nd crank web 33 Crank pin 34 Crank journal (torque transmission part)
40 Center hole 41 Pin hole 43 Arc groove

Claims (3)

In the crankshaft in which one end portion of the crank pin passed between the first and second crank webs is fitted into a pin hole formed in the first crank web,
A center hole formed in a central portion of the first crank web, partially overlapping the pin hole, and into which a bearing is fitted;
In accordance with the shape of the portion of the bearing that protrudes from the center hole to the pin hole side, an arcuate groove portion that is recessed and formed on the outer peripheral surface of the one end portion of the crank pin;
Crankshaft with The crank pin is formed integrally with the second crank web;
The crankshaft according to claim 1, wherein the second crank web is provided with a torque transmission unit to which a drive source or a load is connected. The crankshaft according to claim 1 or 2,
A press machine comprising: a ram coupled to the crankshaft via a connecting rod.

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