JPS6058322B2 - Crank drive mechanism for soil compaction equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a crank drive mechanism for an earth compaction device, and this mechanism includes a crankshaft and a connecting rod that are connected to each other by two axially parallel eccentric elements. The two eccentric elements are rotatable and fixed relative to each other in order to vary the total eccentricity.

Such a mechanism is intended to vary the length of the stroke of the articulating rod.

With arrangements of this type that are known in the art, adjustment of the length of the stroke is either difficult or requires substantial expense to construct.

It is therefore an object of the invention to provide a crank drive mechanism, as stated at the outset, in which the length of the stroke can be changed and fixed quickly and simply, without the need for expensive mechanisms. It is to be.

According to the present invention, this problem is solved as follows.
That is, a first eccentric element having a plurality of recesses and a second eccentric element having one fixing bolt are provided, and the fixing bolt can be arbitrarily inserted into one of the plurality of recesses. fixing and changing the angular position between the two eccentric elements by doing so, allowing said fixing bolt to be assembled and arranged on the eccentric element to be coupled thereto; A bolt is inserted into one recess of the first eccentric element and occupies only one specific position of the eccentric element, and the relative angular position between the two eccentric elements connected by this fixing bolt is predetermined. and that the plurality of recesses are constructed and arranged so as to assume only one angular position. Therefore, the position of the fixing bolt determines the total eccentricity,
Also, the position and shape of the fixing bolt in the plurality of recesses are selected and adapted to each other to provide a specific position of the fixing bolt and a specific angle of the first eccentric element with respect to the second eccentric element. Since when holding the position it is fixed in only one of the recesses, the length of the stroke of the crank drive is also determined. When refitting the fixing bolt, a plurality of bolts having different shapes may also be replaced.

This meaning is also intended to apply to structures that allow the insertion of fixing bolts connected thereto at different locations in the eccentric element, and in which the fixing bolt is always installed in the same position in the eccentric element. However, it is applied to structures where refitting is carried out by rotation about a longitudinal axis or reversal with respect to its eccentric element. After all, the meaning of refitting includes movement, redirection and reinsertion as well as rotation of the fixing bolt relative to the eccentric element, insofar as the fixing bolt is arranged on the eccentric element. According to a preferred embodiment of the crank drive mechanism according to the invention, the first eccentric element is rotatably supported in an eccentric bearing (for example a shaft neck or bore) in the second eccentric element.

However, if any of these eccentric elements are interposed in the middle,
Support by one or more components is also possible. According to one variant of the preferred embodiment of the structure according to the invention, the fastening bolt is capable of being refitted around its longitudinal axis, and the part inserted into the recesses is of its permanent bolt. It has a cross section that is eccentric with respect to the vertical axis.

The engaging part of the fixing bolt can therefore have a symmetrical cross-section with respect to the center of this engaging part, but this engaging part can be offset (eccentric) with respect to the longitudinal axis of the fixing bolt. Become. It is also possible to provide an engagement part with a certain cross-section, for example oval or polygonal, and arranged concentrically with respect to the longitudinal axis of the bolt.

In order to facilitate the insertion of a fastening bolt into one of the recesses, it is proposed to configure the engagement area of the fastening bolt and/or the recess, so that the recess is aligned in the direction of the longitudinal axis of the fastening bolt. A tapered slope is added. This is because the crank drive mechanism requires its full eccentricity, so the stroke length (eccentric distance) of the crank drive is selected in advance, and the fixing bolt is simply dropped into the appropriate recess when the crank drive starts. It is particularly advantageous when As an alternative to a structure with recesses of different shapes, a plurality of recesses are provided at different distances from the relative rotation axis of the two eccentric elements. Such a structure can be produced very economically and is particularly advantageous if the fixing bolt is rotatable relative to the eccentric element for refitting and has an engagement area eccentric with respect to its axis of rotation and is therefore This is the case in that the engagement area may also have a circular cross-section. In a preferred embodiment of the eccentric element, in order to ensure that the fixing bolt is more quickly dropped into the recess of the first eccentric element so as to engage it in a preselected position, the fixing bolt is An insertion recess for a fixing bolt is provided in front of each recess seen in the direction of rotation. This recess may take the form of an inclined surface inclined in the direction towards the recess, but also the engagement of the fastening bolt measured in the radial direction of the eccentric element when the fastening bolt is dropped into the preselected position of said recess. It can also be configured as a groove with a width matching the diameter of the joint. In such an embodiment, a fixing bolt depressed into said recess connects two eccentric elements to each other, and an insertion recess adjacent to said recess connects the two eccentric elements to each other. Preferably, the area is configured to be no deeper than the depth of the recess, so that these eccentric elements have free slack in both rotational directions.

These insertion recesses can also serve as engagement points for fixing bolts and also allow the recesses to have a cylindrical shape, so that the recesses are not only easy to produce but also allow the fixing bolts to It also has a supporting effect on the walls of this recess, which is an improvement comparable to a conically shaped one. Further features, advantages and details of the invention can be found in the appended claims and/or in the following description, as well as examples of three particularly advantageous embodiments of a crank drive mechanism according to the invention for use in a vibratory tamping device. This is clarified by the attached drawings. A vibratory tamping device, shown in FIG. 1 and characterized by a crank drive whose stroke length is adjusted according to the invention, is supported on a tamping plate 10, which tamping plate is connected via a so-called tamping bed 12 to a drive system which essentially comprises an internal combustion engine 14 and a transmission 16 .

A guide handle 18 is provided for guiding the vibrating tamper. The transmission 16 comprises a crank drive which converts the rotational movement of the drive shaft of the internal combustion engine into a vertical reciprocating movement of the tamping plate 10. The transmission device 16 will be explained with reference to FIG.

The drive shaft 20 has a pinion 22 formed on the shaft, and is rotatably supported by the machine casing 19. The pinion meshes with a gear outer ring 24 on the crankshaft 26,
The crankshaft 26 also includes a crank pin 34 supported in the machine housing 19 by rolling bearings 28 and 30 and eccentric from the axis of rotation of the crankshaft. Via a plain bearing 36, the crankpin supports an eccentric bushing 38 whose cylindrical peripheral surface 40 has a first eccentricity with respect to the axis of the crankpin, which is representative of a second eccentric member. Form a member. By means of a needle bearing 44, the eccentric bushing 38 is rotatably supported on a connecting rod 46, which is slidably guided by a guide path 50 of the tamping table 12 via a support pin 48 and is connected to a diaphragm. By driving the shaft 52 mounted above, a reciprocating motion in the vertical direction is transmitted to said shaft.

According to the invention, a hole 60, more particularly a stepped hole, is provided in the crankshaft 26 parallel to its axis of rotation, which is eccentric with respect to the axis of rotation, so that the fixing bolt 62 can rotate and slide freely. guided into said hole.

The fixing bolt is provided with a handle 64 and a head 66, the head 66 having a circular fiber section 70 which is introduced into the enlarged part of the hole 60 and is eccentric with respect to the hole 60, and this conical section 70 is eccentric. ．． It is adapted to fit into the same conical hole 72 provided in a disc 74 which is integrally formed on the bushing 38. According to the invention, both the cone and the hole 72 have a circular cross section in the embodiment.
Between the stepped hole 60 and the head 66 of the fixing bolt 62, the conical portion 70 of the fixing bolt is inserted into one hole 7 of the eccentric bushing 38.
An engagement spring 78 is provided which biases the engagement spring 78 into the opening 2.

The particular hole 72 into which the conical portion 70 can fit is determined by the rotational angular position of the fixing bolt relative to the crankshaft, as explained below. According to the present invention, the fixing pin 90 attached to the crankshaft 26 and the plurality of holes 92 provided in the handle of the fixing bolt 62
However, the specific position of the fixing bolt 62 is determined, and the number of holes 92 and therefore the number of set positions of the fixing bolt 62 corresponds to the number of holes 72, which in the present invention differ in certain respects and are eccentric. It is arranged in the bush 38.

The fixing bolt 62 can therefore be pulled out to the left of the disc 74 and the fixing pin 90 against the action of the engagement spring 78, according to FIG. 2, and released again by rotation relative to the crankshaft 26. By doing so, the fixing pin 90 again engages one of the holes 92 and the crankshaft 26 and the eccentric bush 38
As a result of the relative rotation between them, the conical part 70 of the fixing bolt 62 can engage in one of the other holes 72 of the eccentric bushing 38 (pre-selection action).

As shown in FIG. 5, the eccentric bushing 38 is provided with three holes in the disk 74 in the illustrated embodiment, namely one hole 72a and two holes 72b;
The two holes 72b are located symmetrically with respect to the former hole 72a, but are located close to the crank pin 34.

The eccentricity of the conical portion 70 of the fixing bolt 62 and the positions of the two holes 92 provided in the handle 64 of the fixing bolt meet the following conditions. That is, in the position of the fixing bolt when the fixing pin 90 is engaged in one of the two holes 92, the conical portion 70 of the fixing bolt can only fit snugly into the hole 72a. , the second position where the fixing bolt can engage is where it can fit snugly into both holes 72b. According to the present invention, the rotation angle position of the eccentric bushing 38 with respect to the crankshaft 26 can be selected in advance to determine two different positions. 72a, the amount of eccentricity between the crank pin 34 and the eccentric portion 40 increases (this state is similar to the second
On the other hand, when the fixing bolt 62 is fitted into one of the holes 72b, the eccentricity of the crank pin 34 is reduced by the eccentricity of the eccentric portion 40. As a result, in one of the above cases the stroke of the shaft 52 and thus of the diaphragm 10 will be longer, and in the other case it will be shorter. According to the invention, a centrifugal clutch 100 is arranged between the internal combustion engine 14 and the drive shaft 20, so that the crankshaft 26 is driven at relatively low rotational speeds of the internal combustion engine 14.

If the fixing bolt 62 were pulled to the left in FIG. 2, the weight of the device would force the eccentric bushing 38 to its top dead center position; are arranged facing the fixing bolt 62.

If the fixing bolt is rotated to such a position that it cannot fit into hole 72a but can only fit into one of holes 72b, the device will start according to the invention. Since the angle of rotation for each of the holes 72b is the same, the sequence of engagement of the fixing bolt 62 is independent of the direction of rotation of the internal combustion engine. Second
Although the embodiment shown in FIGS. 1-5 provides two adjustable stroke lengths and allows markings corresponding to the stroke lengths to be placed on the handle 64 as shown in FIG. In the modified embodiment shown in FIGS. 6 and 7, it is possible to set three different strokes.

However, the two embodiments are very similar to each other and there are only differences between them as explained below. In the embodiment shown in FIGS. 6 and 7, the fixing bolt 62'' has an octagonal head 66'' which is connected to an octagonal hole 96'' in the crankshaft 2''.
” to fit snugly.

A fixing bolt 6 is provided at the location of the eccentric cone portion 70 in the first embodiment.
There is a conical part 7' concentric with the longitudinal center axis of the eccentric bushing 3', which has an elliptical cross section and is connected to the disk 7 of the eccentric bushing 3'.
``Four holes 72a'', 72b'' and 72C provided in
Hole 72b'' is arranged in mirror-like symmetry with respect to hole 72a'', while hole 72C'' forms a fourth hole. As can be readily seen with reference to FIGS. 6 and 7, holes 72a'' are combined for the longest stroke, holes 72C'' are combined for the shortest stroke, while each of the holes 72b'' corresponds to the intermediate stroke.According to the invention, the holes 72a'', 72b''
and 72C'' are arranged so that the oval conical portion 7'' fits only into a specific hole among the holes 72a'' to 72C'' at each possible position of the fixing bolt 62, and as a result,
Each rotational angular position of the fixing bolt will correspond to a specific stroke length. In a third embodiment, shown in FIGS. 8 and 9, the step is adapted to more quickly insert the fastening bolt into the recess so as to engage it at a preselected position of the fastening bolt. ing.

At this end, an insertion recess 73a'' or 73b'' is formed in the hole 72a'' or 72'' when viewed in the direction in which the fixing bolt 62'' acts.
b'', and in a preferred embodiment constitutes a circular arcuate groove.

The width of the groove, measured in the radial direction, corresponds to the diameter of the cylindrical eccentric 70'' of the fixing bolt 62''. In order to connect the two eccentric elements - the crankshaft 26 or 26'' and the eccentric bushing 38'' to each other without loosening in both directions of rotation, according to the invention the fixing bolt 62'' is inserted into the hole 72a''.
Insertion recesses 73a'' and 73b'' are provided which have a shallower depth than when engaging ``and 72b''''.

The direction of rotation of the eccentric bushing 38'' relative to the fixing bolt which has not yet been inserted into the hole is indicated by an arrow in FIG.

When the fixed state is released, the weight of the machine causes the eccentric bush 3' to be placed in a position such that the crank pin 34 is at its top dead center - the position of this eccentric bush 38' is shown in FIG. Since it rotates at the same time, one group is provided with one hole and connected to the insertion recess so that the fixing bolt is inserted into that hole immediately or after a short time after the centrifugal crank 100 is engaged. According to the third illustrated embodiment, the hole 72a'' and the insertion recess 73a'''' are arranged at the bottom of the eccentric bushing 381. In other group embodiments 72b'''', 73bI) are arranged in a rotational direction as close as possible to the first group (72a'''', 73a'' in this embodiment). Since it is only necessary to pull the fixing bolt, it is possible to obtain a crank drive mechanism in which a specific length of the stroke or a change in the length of the stroke can be set practically easily.

The length of the required stroke can thus be preadjusted, and it is a feature of the invention that the slow start-up of the vibratory tamping device automatically moves the two eccentric elements into ``reciprocal'' relation, i.e., fixed. It is to be fixed in a rotational angular position that corresponds to the preselected position of the bolt.Of course, other suitable fasteners can be employed in place of the fixing bolt.

[Brief Description of the Drawings] Fig. 1 is a perspective view of the vibrating tamping device, Fig. 2 is a sectional view of the transmission device of the vibrating tamping device taken along line 2-2 in Fig. 1, and Fig. Figure 3 is an enlarged view of the engaging part of the fixing bolt and its surroundings when the fixing bolt is retracted, Figure 4 is the same as Figure 3 but with the fixing bolt in action, and Figure 5 is a sectional view taken along the line 5-5 in Fig. 2, Fig. 6 is a partially modified version of the one shown in Fig. 2, and Fig. 7 is a sectional view taken along the line 7-7 in Fig. 6. A sectional view, FIG. 8 is a view corresponding to FIGS. 5 and 6 showing the third embodiment of the eccentric bushing (bearing sleeve), and FIG. 9 is a view with the front part of the connected fixed bolt cut away. FIG. 9 is a cross-sectional view taken along line 9-9 of FIG. 8; 10... tamping plate, 12... tamping table, 14... internal combustion engine, 16... transmission device, 18... guide handle, 19. ...Machine housing,
20... Drive shaft, 26, 26''... Crankshaft, 34... Crank pin, 38, 3'', 3''
...Bush, 40・Bush surface, 46・
...Connecting rod, 52...Shaft, 60...Hole, 62, 62", 62"...Fixing bolt, 64
...Handle, 70,7'', 70■...Cone part, 72,72a,72a'',72a'''',72b,7
2b'', 72b'', 72C''...dent or hole,
73a'', 73b''... hollow, 74...
·disk.

Claims (1)

[Scope of Claims] 1. A crank drive mechanism for an earth compaction device, which has a crankshaft 26 and a connecting rod 46 that are connected to each other so as to operate, the crankshaft 26 has a crankshaft 26 and a connecting rod 46. A crank pin 34 is provided which supports a bush 38 which is eccentric with respect to the axis of rotation of the crankshaft and which is eccentric with respect to the axis of rotation of the crankshaft, the bush 38 being rotatably attached to the crank pin 34 and the connecting rod 46 being eccentric with respect to the rotation axis of the crankshaft. A crank drive comprising two eccentric elements 38, 26 which are rotatably attached to the bush 38, and which are rotatable and fixable with respect to each other in order to change the total eccentricity between the crankshaft 26 and the connecting rod 46. In the mechanism, the first eccentric element 38 is provided with a plurality of recesses 72 and the second eccentric element 26 is provided with one of said recesses for fixing and changing the angular position between these eccentric elements 26, 38. A fixing bolt 62 is provided which can be inserted optionally into the second eccentric element 26 , the specific position of this fixing bolt 62 relative to the second eccentric element 26 and its angular position corresponding to the specific position of said fixing bolt 62 . Eccentric element 3
The fixing bolt 62 is configured such that it can only be inserted into a predetermined recess 72 of the first eccentric element 38 in a predetermined angular position between 8 and 26. A crank drive mechanism for a soil compaction device, characterized in that it is arranged in a second eccentric element (26) cooperating therewith, and that said plurality of recesses (72) are constructed and arranged. 2. The crank drive mechanism for an earth compaction device according to claim 1, wherein the first eccentric element 38 is rotatably supported by eccentric bearings 44, 36 of the second eccentric element 26. 3. The fixing bolt 62 is refittable about its longitudinal axis, and the part 70 inserted into the recess 72 has a cross section that is eccentric with respect to the longitudinal axis of the fixing bolt. Or a crank drive mechanism for an earth compaction device according to item 2. 4. The soil compaction device according to any one of the above claims, wherein the fixing bolt 62 and/or the recess 72 have a tapered slope in the direction of the longitudinal axis of the bolt. Crank drive mechanism. 5. The recited feature of any one of the claims, characterized in that the recesses 72a, 72b are at different distances from the axis of rotation of the two eccentric elements 26, 38 (the axis of the crank pin 34). Crank drive mechanism for hardening equipment. 6. Any one of the preceding claims, characterized in that the fixing bolt 62 is rotatable for refitting to the eccentric element 26 and has an engaging portion 70 eccentric to its rotation axis. Crank drive mechanism for soil compaction equipment described in . 7. A crank drive mechanism for an earth compaction device as set forth in any one of the preceding claims, wherein the engaging portion 70' of the fixing bolt 62' has a cross section significantly different from a circular one. 8. The recess 72 has a cross section of a shape and size that matches the cross section of the engaging portion 70 of the fixing bolt 62, so that the recess fits into the fixing bolt without a gap. A crank drive mechanism for an earth compaction device according to any one of the claims. 9. One eccentric element 26 has a tube 60 into which a fixing bolt 62 can be inserted in different positions, such that in the inserted position the fixing bolt cannot rotate. A crank drive mechanism for a soil compaction device as set forth in any one of the claims. 10. A crank drive mechanism for a soil compaction device as claimed in any one of the preceding claims, characterized in that it has a spring 78 adapted to force the fixing bolt 62 into its engaged position. 11. According to any one of the preceding claims, characterized in that the recesses 72a', 72b', 72c' have different orientations with respect to the axis of rotation between the two eccentric elements 26', 38'. Crank drive device for soil compaction equipment. 12 Eccentric element 38 with recesses 72a'', 72b''
Insertion recesses 73a'' and 73b'' for fixing bolts are provided in front of each recess when viewed in the rotational direction of the fixing bolt 62''.
A crank drive mechanism for an earth compaction device as set forth in any one of the claims. 13. The recess (e.g. 72a'') is formed deeper than the adjacent part of the insertion recess (e.g. 73a''), the latter being connected via a recessed step so that the step fits into the recess. 13. The crank drive mechanism for an earth compaction device according to claim 12, further comprising a locking portion for an engaging portion 70'' of the fixing bolt 62''. 14. The crank drive mechanism for an earth compaction device according to any one of claims 3, 8, and 12, wherein the engaging portion 70'' of the fixing bolt 62'' has a cylindrical shape.