Impact mechanism layout

Abstract

The present invention provides a hammer drill and / or chisel hammer (100) having a drive motor (70), an impact mechanism (10) and a tool assembly (50) for assembling a tool (110), wherein the impact mechanism (10) has an anvil (30) which is axially displaceable in an anvil guide (20) and acts on the tool (110), wherein the impact mechanism (10) has a lost motion impact damping element (11) which acts between the anvil (30) and the tool assembly (50), and wherein the impact mechanism has a guide housing (80) which is at least partially engaged around the anvil (30) and / or the tool assembly (50), wherein an additional lost motion impact damping element (31) is provided which acts between the tool assembly (50) and the guide housing (80).

Description

Technical Field

[0001] The present invention relates to a hammer drill and / or chisel hammer having a drive motor, an impact mechanism, and a tool assembly for assembling a tool. The impact mechanism has an anvil that is axially displaceable in an anvil guide and acts on the tool. The impact mechanism is equipped with a lost motion impact damping element that acts between the anvil and the tool assembly. The impact mechanism has a guide housing that at least partially engages around the anvil and / or the tool assembly. Background Art

[0002] Drill hammers and / or chiseling hammers of the type mentioned at the outset are generally known from the prior art.

[0003] Lost motion impact damping elements and rebound impact damping elements, preferably in the form of elastomeric damping elements, are used to keep force peaks and vibrations on downstream components as low as possible. When the impact mechanism is in the operating position, the anvil bears against a typically provided rebound impact disk after each impact, and this is absorbed by the rebound impact damping element.

[0004] If the contact force is too low or the concrete / stone being worked on becomes detached, a lost motion impact can occur. This means that the entire impact energy must be absorbed by the hammer, and in particular by the tool assembly itself. To protect downstream components from the force peaks of a lost motion impact, a lost motion impact damping element is typically used. The lost motion impact damping provided by the lost motion impact damping element influences the return speed of the anvil after a lost motion impact and thus the deactivation behavior of the hammer. Summary of the Invention

[0005] The object of the present invention is to provide a hammer drill and / or chisel hammer in which the load on the tool assembly is relatively reduced.

[0006] This object is achieved by providing an additional lost motion impact damping element that acts between the tool assembly and the guide housing. The present invention has the advantage that a relatively low anvil return speed can be achieved by two damping elements operating against each other. When the lost motion impact damping element rebounds during the anvil's return movement, i.e., after a lost motion impact, the additional lost motion impact damping element acting between the tool assembly and the guide housing is compressed, so that the anvil is only accelerated to a relatively small extent. This, in turn, results in a relatively reduced load on the tool assembly.

[0007] In a particularly preferred embodiment, the tool assembly is movable in the axial direction relative to the guide housing and / or is at least partially arranged in the guide housing. It has been found to be advantageous if the impact mechanism has a rebound impact damping element and an additional rebound impact damping element. The rebound impact damping element preferably acts between the anvil and the guide housing. It has been found to be advantageous if the additional rebound impact damping element is arranged to act between the tool assembly and the guide housing. As a result of the cooperation of the additional lost motion impact damping element and the additional rebound impact damping element, the tool assembly can be mounted in a floating manner, as a result of which a large part of the impact energy of the anvil can already be attenuated.

[0008] It has been found to be advantageous if the additional lost motion impact damping element and / or the additional rebound impact damping element are radially spaced further away from the anvil than the lost motion impact damping element and / or the rebound impact damping element. With respect to the guide housing, the additional lost motion impact damping element can be supported in the axial direction by the guide bearing.

[0009] In a particularly preferred embodiment, the force from the tool assembly is introduced into the unit consisting of the additional lost motion impact damping element and the additional rebound impact damping element via a ring that protrudes radially from the tool assembly. It has been found to be advantageous if the ring or pin engages between the additional lost motion impact damping element and the additional rebound impact damping element relative to the axial direction of the anvil. The ring or pin can be clamped in place axially between the additional lost motion impact damping element and the additional rebound impact damping element.

[0010] In a particularly preferred embodiment, the anvil is provided with a contact element which is arranged to contact a lost motion impact stop surface on one side and a rebound impact stop surface on the other side. It has been found to be advantageous if the lost motion impact stop surface is formed on a lost motion impact stop ring included in the tool assembly and / or if the rebound impact stop surface is formed on a rebound impact stop ring included in the tool assembly.

[0011] In a particularly preferred embodiment, the impact mechanism comprises a lost motion impact wedge ring and / or a rebound impact wedge ring. The lost motion impact wedge ring can be arranged between the first bearing of the anvil guide and the lost motion impact damping element. It has been found to be advantageous if the rebound impact wedge ring is arranged between the second bearing of the anvil guide and the rebound impact damping element. The first bearing and / or the second bearing can be in the form of a plain bearing or a rolling bearing.

[0012] In a particularly preferred embodiment, the lost motion impact wedge ring rests only on the first bearing on its side facing away from the lost motion impact damping element and in the axial direction. The rebound impact wedge ring can rest only on the second bearing on its side facing away from the rebound impact damping element and in the axial direction.

[0013] In a particularly preferred embodiment, the contact element is formed separately from the anvil. Advantageously, the contact element can be resiliently clamped in place in the axial direction between the lost motion impact damping element and the rebound impact damping element. It has been found to be advantageous if the contact element is movable in the axial direction relative to the anvil. In a particularly preferred embodiment, the anvil has a channel extending in the axial direction. Particularly preferably, the contact element is permanently engaged with the channel.

[0014] As an alternative to forming the contact piece separately from the anvil, the contact piece can be formed in one piece with the anvil. It has been found to be advantageous if the lost motion impact damping element, the rebound impact damping element, the additional lost motion impact damping element and / or the additional rebound impact damping element are configured as an elastomer.

[0015] Further advantages will become apparent from the following description of the accompanying drawings. A number of different exemplary embodiments of the present invention are shown in the accompanying drawings. The drawings and the description contain many combined features. Those skilled in the art will also readily consider these features individually and combine them to produce useful further combinations. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] In the accompanying drawings, the same and similar parts are denoted by the same reference numerals. In the accompanying drawings:

[0017] Figure 1 A preferred exemplary embodiment of a hammer drill and / or chisel hammer according to the present invention is shown; and

[0018] Figure 2 A preferred exemplary embodiment of the impact mechanism is shown. DETAILED DESCRIPTION

[0019] Figure 1 A preferred exemplary embodiment of a drill hammer and / or chisel hammer 100 according to the present invention is shown. The drill hammer and / or chisel hammer 100 is equipped with a drive motor 70, an impact mechanism 10, and a tool assembly 50 for assembling a tool 110. The impact mechanism 10 and the drive motor 70 are arranged in a housing 90 of the drill hammer and / or chisel hammer 100.

[0020] The impact mechanism 10 has an anvil 30 which is displaceable in an anvil guide 20 in an axial direction AR and acts on a tool 110. The anvil guide 20 is realized by a first bearing 21 and a second bearing 23 (here in the form of rolling bearings, for example), which bear against the tool mount 50 in the radial direction RR and in the axial direction AR, respectively.

[0021] The impact mechanism 10 has a lost motion impact damping element 11, which acts between the anvil 30 and the tool assembly 50 (via a lost motion impact stop ring 56). The impact mechanism 10 also has a guide housing 80, which is at least partially engaged around the anvil 30 and the tool assembly 50. According to the invention, an additional lost motion impact damping element 31 is provided, which acts between the tool assembly 50 and the guide housing 80. The tool assembly 50 is movable in the axial direction AR relative to the guide housing 80 and is at least partially arranged in the guide housing 80. If the tool assembly 50 is moved further out of the guide housing 80 in the axial direction AR, i.e. moved to Figure 1 On the left side in FIG, the elastic additional lost motion impact damping element 31 is compressed.

[0022] from Figure 1 It is also obvious that the impact mechanism 10 is equipped with an elastic rebound impact damping element 13 and an elastic additional rebound impact damping element 33. In this case, the rebound impact damping element 13 acts between the anvil 30 and the guide housing 50 via the rebound impact stop ring 55. The additional rebound impact damping element 33 acts between the tool assembly 50 and the guide housing 80. In this case, the introduction of force from the tool assembly 50 into the unit consisting of the additional lost motion impact damping element 31 and the additional rebound impact damping element 33 occurs via the ring 51 protruding from the tool assembly in the radial direction RR. If the tool assembly 50 moves further in the axial direction AR into the guide housing 80, i.e., to Figure 1 , the elastic additional lost motion impact damping element 31 is unloaded and the additional rebound impact damping element 33 is compressed. The ring 51 can be clamped in place in the axial direction AR between the additional lost motion impact damping element 31 and the additional rebound impact damping element 33. Figure 1 It is evident that the ring 51 engages between the additional lost motion impact damping element 31 and the additional rebound impact damping element 33 with respect to the axial direction AR.

[0023] The anvil 30 is provided with a contact piece 35 which is arranged to be in contact with the lost motion impact stop surface 12 on one side and with the rebound impact stop surface 14 on the other side. Figure 1 In the exemplary embodiment of the present invention, the contact member 35 is formed in one piece with the anvil 30. In this case, the lost motion impact stop surface 12 is formed on a lost motion impact stop ring 56 included in the tool assembly 50. The rebound impact stop surface 14 is in turn formed on a rebound impact stop ring 55 included in the tool assembly 50.

[0024] Another preferred exemplary embodiment of the impact mechanism 10 is Figure 2. The impact mechanism 10 has an anvil 30 that is displaceable in the axial direction AR in an anvil guide 20. The anvil guide 20 is realized by a first bearing 21 and a second bearing 23 (here, for example, in the form of rolling bearings), which bear against the tool mount 50 in the radial direction RR and the axial direction AR, respectively.

[0025] and Figure 1 In contrast to the exemplary embodiment shown, Figure 2 In the exemplary embodiment of FIG. 3 , the contact piece 35 is formed separately from the anvil 30. The anvil 30 has a channel 37 extending in the axial direction AR, and the contact piece 35 can slide in the channel in the axial direction AR. Figure 2 It is evident that the contact piece 35 is movable both relative to the anvil 30 and relative to the tool assembly 50 , as viewed in each case in the axial direction AR. The contact piece 35 is permanently engaged with the channel 37 .

[0026] exist Figure 2 In the state shown, i.e. during the lost motion impact, the contact member 35 comes into contact with the right stop 38 of the channel, or impacts said stop (the anvil 30 is in Figure 2 During the rebound impact (not shown here), the contact member 35 then comes into contact with the left stop 39 of the channel 36 or strikes the stop (the anvil 30 moves to the left in the Figure 2 to the right in the middle).

[0027] Figure 2 The impact mechanism in FIG. 1 has a lost motion impact damping element 11, which acts between the anvil 30 and the tool mount 50 on one side via a lost motion impact wedge ring 57 and the first bearing 21 and on the other side via a lost motion impact stop ring 56 and the contact piece 35. In addition, a rebound impact damping element 13 is provided, which acts between the anvil 30 and the guide housing 50 on one side via a rebound impact wedge ring 58 and the second bearing 21 and on the other side via a rebound impact stop ring 55 and the contact piece 35.

[0028] from Figure 2 It is apparent that the lost motion impact wedge ring 57 is arranged between the first bearing 21 of the anvil guide 20 and the lost motion impact damping element 10. The rebound impact wedge ring 58 is arranged between the second bearing 23 of the anvil guide 20 and the rebound impact damping element 13. In this case, the lost motion impact wedge ring 57, on its side facing away from the lost motion impact damping element 10 and in the axial direction AR, bears only on the first bearing 21. The rebound impact wedge ring 58, on its side facing away from the rebound impact damping element 13 and in the axial direction, bears only on the second bearing 23.

[0029] The contact piece 35, separated from the anvil 30, is resiliently clamped in place in the axial direction AR between the lost motion impact damping element 11 and the rebound impact damping element 13. In this regard, during operation of the impact mechanism 10, no "conventional" impact of the contact piece 35 against the lost motion impact stop ring 56 or the rebound impact stop ring 55 occurs.

[0030] like Figure 1 In the exemplary embodiment, Figure 2 In the exemplary embodiment in , an additional lost motion impact damping element 31 is also provided, which acts between the tool mount 50 and the guide housing 80. Relative to the guide housing 80, the additional lost motion impact damping element 31 is supported in the axial direction AR by a guide bearing 85.

[0031] from Figure 2 It is also evident that the impact mechanism 10 is equipped with an elastic rebound impact damping element 13 and an elastic additional rebound impact damping element 33. In this case, the rebound impact damping element 13 acts between the anvil 30 and the guide housing 50 via a rebound impact stop ring 55, a rebound impact wedge ring 58, and a contact piece 35. The additional rebound impact damping element 33 acts between the tool mount 50 and the guide housing 80. In this case, the force is introduced from the tool mount 50 into the unit consisting of the additional lost motion impact damping element 31 and the additional rebound impact damping element 33 via a ring 51 protruding from the tool mount in the radial direction RR.

[0032] As a result of the cooperation of the additional lost motion impact damping element 31 and the additional rebound impact damping element 33 , in this exemplary embodiment as well, the tool assembly 50 is mounted in a floating manner, with the result that a large portion of the impact energy of the anvil 30 can already be damped.

[0033] List of Reference Numerals

[0034] 10 Impact mechanism

[0035] 11 Lost motion impact damping element

[0036] 12 Lost travel impact stop surface

[0037] 13 Rebound impact damping element

[0038] 14 Rebound hits the stop surface

[0039] 20 anvil guide

[0040] 21, 23 rolling bearings

[0041] 30 anvil

[0042] 31 Additional lost motion impact damping element

[0043] 33 Additional rebound impact damping element

[0044] 35 contacts

[0045] 36 channels

[0046] 38 right channel stop

[0047] 39 left channel stop

[0048] 50 tool assembly parts

[0049] 51 rings

[0050] 55 rebound impact stop ring

[0051] 56 lost motion impact stop ring

[0052] 57 Idle impact wedge ring

[0053] 58 rebound impact wedge ring

[0054] 70 drive motor

[0055] 80 guide housing

[0056] 85 guide support

[0057] 90 shell

[0058] 100 hammer drills and / or chiseling hammers

[0059] 110 Tools

[0060] AR axial direction

[0061] RR radial direction

Claims

1. A hammer drill or a chisel hammer (100) comprising a drive motor (70), an impact mechanism (10) and a tool assembly (50) for assembling a tool (110), wherein: The impact mechanism (10) has an anvil (30) which is axially displaceable in an anvil guide (20) and acts on the tool (110), wherein the impact mechanism (10) has a lost motion impact damping element (11) which acts between the anvil (30) and the tool assembly (50), and wherein the impact mechanism (10) has a guide housing (80) which is at least partially engaged around the anvil (30) and / or the tool assembly (50), characterized in that a An additional lost motion impact damping element (31) acts between the tool assembly (50) and the guide housing (80), the anvil (30) is provided with a contact piece (35) which is arranged to contact the lost motion impact stop surface (12) on one side and the rebound impact stop surface (14) on the other side, and the contact piece (35) is formed separately from the anvil (30) and is elastically clamped in place in the axial direction between the lost motion impact damping element (11) and the rebound impact damping element (13).

2. The hammer drill or chisel hammer (100) according to claim 1, It is characterized by: The tool assembly (50) is movable in an axial direction (AR) relative to the guide housing (80) and / or is at least partially arranged within the guide housing (80).

3. The hammer drill or chisel hammer (100) according to claim 1, It is characterized by: The impact mechanism (10) has the rebound impact damping element (13) and an additional rebound impact damping element (33), wherein the rebound impact damping element (13) acts between the anvil (30) and the guide housing (80), and the additional rebound impact damping element (33) acts between the tool assembly (50) and the guide housing (80).

4. A hammer drill or chisel hammer (100) according to claim 3, It is characterized by: The introduction of force from the tool mount (50) into the unit consisting of the additional lost motion impact damping element (31) and the additional rebound impact damping element (33) occurs via a ring (51) protruding from the tool mount in the radial direction (RR).

5. The hammer drill or chisel hammer (100) according to claim 4, It is characterized by: The ring (51) engages between the additional lost motion impact damping element (31) and the additional rebound impact damping element (33) with respect to the axial direction (AR).

6. The hammer drill or chisel hammer (100) according to claim 1, It is characterized by: The lost motion impact stop surface (12) is formed on a lost motion impact stop ring (56) included in the tool assembly (50) and / or the rebound impact stop surface (14) is formed on a rebound impact stop ring (55) included in the tool assembly (50).

7. The hammer drill or chisel hammer (100) according to claim 6, It is characterized by: The impact mechanism (10) has a lost motion impact wedge ring (57) and a rebound impact wedge ring (58), wherein the lost motion impact wedge ring (57) is arranged between the first bearing (21) of the anvil guide (20) and the lost motion impact damping element (11), and the rebound impact wedge ring (58) is arranged between the second bearing (23) of the anvil guide (20) and the rebound impact damping element (13).

8. The hammer drill or chisel hammer (100) according to claim 7, It is characterized by: The lost motion impact wedge ring (57) rests only on the first bearing (21) on its side facing away from the lost motion impact damping element (11) and in the axial direction (AR), and / or the rebound impact wedge ring (58) rests only on the second bearing (23) on its side facing away from the rebound impact damping element (13) and in the axial direction.

9. The hammer drill or chisel hammer (100) according to claim 1, It is characterized by: The contact member (35) is movable relative to the anvil (30) in an axial direction (AR).

10. The hammer drill or chisel hammer (100) according to claim 9, It is characterized by: The anvil (30) has a channel (37) extending in an axial direction (AR), with the contact member (35) being permanently engaged with the channel.

11. The hammer drill or chisel hammer (100) according to claim 3, It is characterized by: The lost motion impact damping element (11), the rebound impact damping element (13), the additional lost motion impact damping element (31) and the additional rebound impact damping element (33) are configured as elastic bodies.

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