Balancing mechanism for reciprocating machine tool, and reciprocating machine tool

Abstract

A balancing mechanism for a reciprocating machine tool. The balancing mechanism is connected to a reciprocating rod (1) of a reciprocating machine tool. The balancing mechanism comprises: a drive disk (3), which can rotate around a rotary shaft (31) thereof, wherein a first driving portion (32) and a second driving portion (33) are fixedly provided on the drive disk, an axis (O 1) of the first driving portion and an axis (O 2) of the second driving portion being collinear with an axis (O 3) of the rotary shaft (31) of the drive disk (3), and being respectively located on two sides of the axis (O 3) of the rotary shaft (31) of the drive disk (3), and the first driving portion (32) being connected to the reciprocating rod (1); and a counterbalance (2), which is connected to the second driving portion (33), wherein a counterbalance assembly is configured to enable a connecting line between the center of gravity of the counterbalance assembly and the center of gravity of the reciprocating rod (1) to be parallel to a reciprocating motion trajectory of the reciprocating rod (1), and when the drive disk (3) rotates around the rotary shaft (31) thereof, the first driving portion (32) and the second driving portion (33) drive the reciprocating rod (1) and the counterbalance (2), respectively, to move in opposite directions.

Description

Balancing mechanism for reciprocating machine tool and reciprocating machine tool Technical Field

[0001] The present invention relates to a balancing device, in particular to a balancing device for a reciprocating machine tool. Background Art

[0002] Reciprocating saws, jigsaws, and similar reciprocating motion tools often require reciprocating motion to achieve an operating result, such as cutting, during operation.

[0003] Based on the working process and principle of reciprocating motion tools, they often generate periodic unbalanced inertial force during operation. This unbalanced inertial force will cause vibration and impact to the tool, thereby affecting the operator's experience and, in severe cases, affecting the service life of the tool.

[0004] Based on this, there is a tendency to add a balancing block to the current reciprocating motion tools, hoping that the balancing block can generate an opposite inertial force during the working process, thereby offsetting the periodic unbalanced inertial force generated during the working process, thereby reducing vibration and impact.

[0005] However, due to its structure and setting position, the existing balance block is not very effective in reducing vibration and impact. In addition, since the center of gravity of the balance block is not on the same straight line as the reciprocating rod of the reciprocating tool, there is a deviation between the line connecting the center of gravity of the reciprocating rod and the balance block and the movement direction of the reciprocating rod. This will cause the added balance block to introduce a new periodically changing torque during the movement process, thereby affecting the setting effect of the balance block.

[0006] Summary of the Invention

[0007] One of the objectives of the present invention is to provide a balancing mechanism for a reciprocating machine tool, which can offset or reduce the periodic unbalanced inertial force generated by the reciprocating machine tool during operation, thereby reducing vibration and impact. At the same time, it can also avoid the generation of additional torque during the balancing process, thereby achieving a better balancing effect.

[0008] To achieve the above-mentioned object, the present invention provides a balancing mechanism for a reciprocating machine tool, which is connected to a reciprocating rod of the reciprocating machine tool, wherein the balancing mechanism includes:

[0009] A drive plate capable of rotating about its own rotation axis, wherein a first drive portion and a second drive portion are fixedly disposed on the drive plate, wherein the axis of the first drive portion and the axis of the second drive portion are collinear with the axis of the drive plate's own rotation axis, and the axis of the first drive portion and the axis of the second drive portion are respectively located on either side of the axis of the drive plate's own rotation axis; wherein the first drive portion is connected to the reciprocating rod;

[0010] a balancing weight assembly including at least a balancing weight, connected to the second driving portion, wherein the balancing weight assembly is arranged so that a line connecting the center of gravity of the balancing weight assembly and the center of gravity of the reciprocating rod is parallel to the reciprocating motion trajectory of the reciprocating rod;

[0011] When the driving disk rotates around its own rotation axis, the first driving part and the second driving part respectively drive the reciprocating rod and the balancing block to move in opposite directions.

[0012] Furthermore, in the balancing mechanism described in the present invention, the first driving portion is configured as an eccentric driving pin axially protruding from the end surface of the driving disk, and the second driving portion is configured as an eccentric circular track groove extending on the end surface of the driving disk.

[0013] Furthermore, in the balancing mechanism described in the present invention, a first bearing is provided between the eccentric driving pin and the reciprocating rod.

[0014] Furthermore, in the balancing mechanism described in the present invention, the balancing weight assembly further includes a connecting pin, the connecting pin is connected to the balancing weight, and the lower end of the connecting pin is inserted into the eccentric circular track groove.

[0015] Furthermore, in the balancing mechanism described in the present invention, a second bearing is provided between the lower end of the connecting pin and the eccentric circular track groove.

[0016] Furthermore, in the balancing mechanism described in the present invention, there is a first eccentricity between the axis center of the first driving part and the axis center of the driving disk's own rotating axis, and there is a second eccentricity between the axis center of the second driving part and the axis center of the driving disk's own rotating axis, which satisfies: the product of the mass of the reciprocating rod and the first eccentricity is approximately equal to the product of the mass of the balancing block assembly and the second eccentricity.

[0017] Furthermore, in the balancing mechanism of the present invention, the center of gravity of the driving disk coincides with the center of its own rotation axis.

[0018] Furthermore, in the balancing mechanism of the present invention, the driving disc is provided with weight-reducing holes and / or trimming portions so that the center of gravity of the driving disc coincides with the center of its own rotation axis.

[0019] Furthermore, the balancing mechanism of the present invention further comprises: a driving element connected to the driving disc to drive the driving disc to rotate around its own axis.

[0020] Furthermore, in the balancing mechanism of the present invention, the driving element includes a motor and a gear shaft, and the gear shaft is connected between the motor and the driving disk.

[0021] Furthermore, in the balancing mechanism described in the present invention, the drive plate is constructed as a first bevel gear, the driving element includes a motor and a second bevel gear, the second bevel gear is connected between the motor and the first bevel gear, and the axial angle between the second bevel gear and the first bevel gear is less than or equal to 90°.

[0022] Furthermore, the balancing mechanism described in the present invention also includes a shell, which has a first cavity for limiting the reciprocating rod and a second cavity for limiting the balancing weight, so that when the driving disk rotates around its own rotation axis, the reciprocating rod and the balancing weight can only move in the axial direction of the reciprocating rod.

[0023] Another object of the present invention is to provide a reciprocating machine tool having low vibration and good user experience.

[0024] Based on this, the present invention further provides a reciprocating machine tool, which includes the balancing mechanism as described above.

[0025] The balancing mechanism described in the present invention can effectively offset or reduce the periodic unbalanced inertial force generated by the reciprocating motion machine tool during operation. At the same time, it can also prevent the balancing block from generating additional torque in the process of performing the balancing function. Therefore, it can effectively reduce the vibration and impact of the reciprocating motion machine tool and greatly improve the user comfort.

[0026] BRIEF DESCRIPTION OF THE DRAWINGS

[0027] FIG1 shows a schematic perspective structural diagram of a balancing mechanism for a reciprocating machine tool according to an embodiment of the present invention.

[0028] FIG. 2 shows a schematic perspective structural diagram of a drive disc of a balancing mechanism for a reciprocating power tool according to an embodiment of the present invention.

[0029] FIG. 3 shows a balancing mechanism for a reciprocating power tool according to one embodiment of the present invention in a state where the reciprocating rod is retracted.

[0030] FIG. 4 shows a state in which the reciprocating rod of the balancing mechanism for a reciprocating power tool according to one embodiment of the present invention is extended.

[0031] Implementation Method

[0032] The balancing mechanism for a reciprocating machine tool and the reciprocating machine tool according to the present invention will be further explained and illustrated below in conjunction with the accompanying drawings and specific embodiments. However, such explanation and illustration do not constitute an undue limitation to the technical solution of the present invention.

[0033] FIG1 shows a schematic perspective structural diagram of a balancing mechanism for a reciprocating machine tool according to an embodiment of the present invention.

[0034] As shown in Figure 1, in some embodiments, a balancing mechanism for a reciprocating machine tool is connected to a reciprocating rod 1 of the reciprocating machine tool, and the balancing mechanism includes a balancing weight assembly and a drive disk 3 that can rotate around its own rotation axis, wherein the balancing weight assembly includes a balancing weight 2.

[0035] FIG. 2 shows a schematic perspective structural diagram of a drive disc of a balancing mechanism for a reciprocating power tool according to an embodiment of the present invention.

[0036] As shown in Figure 2, the driving disk 3 can rotate around its own rotation axis 31, and a first driving part 32 and a second driving part 33 are fixedly provided on the driving disk 3, wherein the first driving part 32 is used to connect with the reciprocating rod 1, and the second driving part 33 is used to connect with the balancing weight assembly including the balancing weight 2.

[0037] The axis O1 of the first driving part and the axis O2 of the second driving part are collinear with the axis O3 of the driving disk's own rotation axis, and the axis O1 and the axis O2 of the first driving part and the axis O2 of the second driving part are respectively located on both sides of the axis O3 of the driving disk's own rotation axis.

[0038] FIG. 3 shows a balancing mechanism for a reciprocating power tool according to one embodiment of the present invention in a state where the reciprocating rod is retracted.

[0039] FIG. 4 shows a state in which the reciprocating rod of the balancing mechanism for a reciprocating power tool according to one embodiment of the present invention is extended.

[0040] As shown in FIG3 and FIG4 , in the present invention, the line connecting the center of gravity of the balancing weight assembly and the center of gravity of the reciprocating rod 1 is arranged parallel to the reciprocating motion trajectory L1 of the reciprocating rod.

[0041] In other words, the line connecting the center of gravity of the balancing weight assembly and the center of gravity of the reciprocating rod 1 can be above or below L1, or offset from L1 in a direction perpendicular to the paper. As long as the line connecting the center of gravity of the balancing weight assembly and the center of gravity of the reciprocating rod 1 is arranged parallel to the reciprocating motion trajectory L1 of the reciprocating rod, the balancing weight can be prevented from generating additional torque when performing its balancing function, thereby reducing vibration and impact of reciprocating machine tools. Of course, in the most ideal embodiment, the line connecting the center of gravity of the balancing weight assembly and the center of gravity of the reciprocating rod 1 is collinear with the reciprocating motion trajectory L1 of the reciprocating rod.

[0042] During operation of the balancing mechanism, the rotation of the driving disc 3 around its own rotation axis 31 drives the reciprocating rod 1 and the balancing weight 2 to move in opposite directions through the first driving part 32 and the second driving part 33 respectively.

[0043] It should be noted that although the rotation of the drive disk will cause the reciprocating rod 1 and the balancing block 2 driven by the first drive part 32 and the second drive part 33 to also have a rotation tendency, by setting a limiting component, the reciprocating rod 1 can only perform linear reciprocating motion in its axial direction during this process, and the balancing block 2 can move in the opposite direction relative to the reciprocating rod 1.

[0044] In the embodiment shown in Figure 1, the movement tendency of the reciprocating rod 1 and the balancing weight in the non-axial direction can be limited by setting a cavity inside the shell 4. For example, a sleeve 41 can be set inside the shell 4 and sleeved on the periphery of the reciprocating rod 1. The sleeve has a first cavity for limiting the reciprocating rod. At the same time, a second cavity 42 can be set at the rear end of the shell to limit the balancing weight. In this way, when the driving disk 3 rotates around its own rotating axis 31, the reciprocating rod 1 and the balancing weight 2 can only move in the axial direction of the reciprocating rod.

[0045] When the drive disc 3 drives the reciprocating rod to perform linear reciprocating motion, the balancing block performing reverse motion can eliminate or reduce the periodic unbalanced inertial force generated by the reciprocating machine tool during operation. In addition, since the line connecting the center of gravity of the balancing block assembly and the center of gravity of the reciprocating rod is arranged parallel to the reciprocating motion trajectory L1 of the reciprocating rod, the balancing block will not generate additional torque when performing a balancing role during the motion process. Therefore, it can effectively reduce the vibration and impact of the reciprocating machine tool and greatly improve the user comfort.

[0046] It should be noted that FIG3 illustrates one embodiment of the drive plate of the present invention. In this embodiment, the first drive portion 32 is configured as an eccentric drive pin protruding axially from the end surface of the drive plate, and the second drive portion 33 is configured as an eccentric circular track groove extending on the end surface of the drive plate. Therefore, in this embodiment, as shown in FIG3 and FIG4 , the reciprocating rod 1 is connected to the eccentric drive pin as the first drive portion 32, while the balancing weight assembly is connected to the eccentric circular track groove as the second drive portion 33.

[0047] Alternatively, in another embodiment, the first driving part 32 may be configured as an eccentric circular track groove and connected to the reciprocating rod through a connecting piece, and the second driving part may be configured as an eccentric driving pin and connected to the balancing block.

[0048] However, considering the movement stroke and efficiency of the reciprocating rod in the reciprocating machine tool, the present invention preferably adopts the first driving portion 32 to be an eccentric driving pin and the second driving portion 33 to be an eccentric circular track groove.

[0049] In a more preferred embodiment, as shown in Figure 2, by adjusting the positions of the first driving part 32 and the second driving part 33 on the driving disk, so that there is a first eccentricity a between the axis O1 of the first driving part and the axis O3 of the driving disk's own rotating axis, and there is a second eccentricity b between the axis O2 of the second driving part and the axis O3 of the driving disk's own rotating axis, it is satisfied that: the product of the mass of the reciprocating rod and the first eccentricity a is approximately equal to the product of the mass of the balancing block assembly and the second eccentricity b.

[0050] This arrangement satisfies the momentum balance of the reciprocating rod and the balancing weight assembly during the reciprocating motion, thereby further optimizing the vibration reduction effect.

[0051] It should be noted that in the above context, the reciprocating rod may include a reciprocating rod body, a connecting piece mounted on the reciprocating rod body, and a cutter head mounted at the end of the reciprocating rod body, so the mass of the reciprocating rod preferably refers to the total mass of all these components.

[0052] Likewise, the balancing weight assembly includes the balancing weight and other accessories connected to the balancing weight, and the mass of the balancing weight assembly preferably refers to the weight of all components.

[0053] In addition, the "approximately equal to" mentioned above means approximately equal to. This expression is used because, in engineering practice, it is difficult to design a balancing mechanism so that the product of the mass of the reciprocating rod and the first eccentricity a is "precisely equal to" the product of the mass of the balancing block assembly and the second eccentricity b. Therefore, for the sake of rigorous expression, "approximately equal to" is used here.

[0054] In some other embodiments, considering that during operation, the reciprocating rod side often has a loaded force, it can also be set as: the product of the mass of the reciprocating rod and the first eccentricity a is less than the product of the mass of the balance weight assembly and the second eccentricity b.

[0055] In some more specific embodiments, such as shown in Figures 3 and 4, the connection between the balancing weight assembly and the second driving part can be achieved through a connecting pin 21, which is part of the balancing weight assembly and is connected to the balancing weight, for example, by an interference fit, and the lower end of the connecting pin 21 is inserted into the eccentric circular track groove.

[0056] Alternatively, in some other more specific embodiments, a connecting pin may not be provided, but a protrusion protruding downward from the main body of the balancing block may be provided on the lower end face of the balancing block. The protrusion is correspondingly provided in the eccentric circular track groove and can also cooperate with the second driving part.

[0057] In addition, in some embodiments, the connecting pin 21 or the protrusion can be directly inserted into the eccentric circular track groove. At this time, during the movement, the connecting pin or the protrusion will slide and rub against the eccentric circular track groove. The friction resistance during the movement is large, and the movement process may be slightly uneven.

[0058] Therefore, in some other embodiments, a second bearing 22, such as a second needle roller bearing, may be provided between the lower end of the connecting pin 21 and the eccentric circular track groove, thereby upgrading the sliding friction to rolling friction, thereby further improving the operational comfort.

[0059] Similarly, a first bearing 36 , such as a first needle bearing, may be provided between the eccentric driving pin serving as the first driving portion 32 and the reciprocating rod 1 , thereby increasing sliding friction to rolling friction to further improve operational comfort.

[0060] Furthermore, in some embodiments of the present invention, the driving disc 3 is preferably arranged so that its center of gravity coincides with the axis of its own rotation axis. This arrangement can further reduce the swing of the driving disc during rotation, thereby further improving the operational stability of the balancing mechanism.

[0061] The gravity distribution of the drive disk 3 can be configured so that the center of gravity of the drive disk 3 coincides with the center of its own rotation axis. For example, in some more specific embodiments, at least one lightening hole 34 can be provided on the drive disk 3. In other more specific embodiments, a portion of the drive disk 3 can be cut away to form a trimmed portion 35. In other embodiments, as shown in FIG2 , both a lightening hole 34 and a trimmed portion 35 can be provided.

[0062] In some other embodiments, the weight distribution of the driving disc can be adjusted by providing a counterweight on the driving disc.

[0063] In the present invention, the driving plate is rotated by the driving action of the driving element.

[0064] As shown in Figures 3 and 4 , in one embodiment, the drive element includes a motor (not shown) and a gear shaft 5. Gear shaft 5 is disposed within a housing via a gear bearing 51. One end of gear shaft 5 is connected to the motor, and the other end is connected to the drive disc 3. This type of balancing mechanism is suitable for use in jigsaws.

[0065] As shown in Figures 3 and 4 , in another embodiment, the drive plate 3 can be configured as a first bevel gear. The drive element includes a motor (not shown) and a second bevel gear 6. The second bevel gear 6 is disposed within the housing via a bevel gear bearing 61 and connected between the motor and the drive plate 3. The angle between the axial direction of the second bevel gear 6 and the first bevel gear is less than 90°. This type of balancing mechanism is suitable for reciprocating saws.

[0066] In some other more specific embodiments, the angle between the axial directions of the second bevel gear 6 and the first bevel gear may also be equal to 90°.

[0067] However, compared to the embodiment in which the angle between the axial direction of the second bevel gear 6 and the first bevel gear is equal to 90°, when the angle between the axial direction of the second bevel gear 6 and the first bevel gear is less than 90°, the space of the reciprocating saw in the axial direction can be further saved, thereby making the structure of the electric tool more compact and the operator's experience better.

[0068] To avoid misunderstanding, it should be noted that for a specific balancing structure, it can be driven by either the gear shaft or the second bevel gear. The illustrations in Figures 3 and 4 are merely for the purpose of visually illustrating the difference between the two. The inclusion of two different implementations in one figure does not imply that the gear shaft and the second bevel gear exist simultaneously.

[0069] Another embodiment of the present invention provides a reciprocating machine tool having the aforementioned balancing mechanism. In some embodiments, the reciprocating machine tool may be a jigsaw, and in other embodiments, a reciprocating saw. It should be noted that the balancing mechanism can be installed on various reciprocating machine tools, including but not limited to reciprocating saws and jigsaws.

[0070] It should be noted that the “up”, “down”, “left” and “right” described herein are for ease of understanding and are exemplary descriptions based on the settings and directions of Figures 1 to 4 and are not intended to limit the present invention.

[0071] It should be noted that the prior art within the scope of protection of the present invention is not limited to the embodiments given in this application document. All prior art that does not contradict the solutions of the present invention, including but not limited to prior patent documents, prior publications, prior public uses, etc., can be included in the scope of protection of the present invention.

[0072] In addition, the combination of the various technical features in this case is not limited to the combination described in the claims of this case or the combination described in the specific embodiments. All technical features recorded in this case can be freely combined or combined in any way unless there is a contradiction between them.

[0073] It should also be noted that the embodiments listed above are merely specific embodiments of the present invention. Obviously, the present invention is not limited to the above embodiments, and similar changes or modifications made therefrom that can be directly derived from or easily conceived by those skilled in the art based on the disclosure of the present invention should fall within the scope of protection of the present invention.

Claims

1. A balancing mechanism for a reciprocating machine tool, which is connected to a reciprocating rod (1) of the reciprocating machine tool, characterized in that, The balance mechanism includes: A driving disk (3) that can rotate around its own rotation axis (31). A first driving part (32) and a second driving part (33) are fixedly arranged on the driving disk. The axis center of the first driving part (32), the axis center of the second driving part (33), and the axis center of the driving disk's own rotation axis (31) are collinear, and the axis center of the first driving part (32) and the axis center of the second driving part (33) are respectively located on both sides of the axis center of the driving disk's own rotation axis (31); wherein the first driving part (32) is connected to the reciprocating rod (1); A balance weight assembly including at least a balance weight (2), which is connected to the second driving part (33). The balance weight assembly is arranged such that the line connecting the center of gravity of the balance weight assembly and the center of gravity of the reciprocating rod is parallel to the reciprocating motion trajectory of the reciprocating rod; Wherein, when the driving disk (3) rotates around its own rotation axis (31), the first driving part (32) and the second driving part (33) respectively drive the reciprocating rod (1) and the balance weight (2) to move in opposite directions.

2. The balance mechanism according to claim 1, wherein, The first driving part (32) is arranged as an eccentric driving pin axially protruding from the end face of the driving disk (3), and the second driving part (33) is arranged as an eccentric circular track groove extending on the end face of the driving disk.

3. The balance mechanism according to claim 2, characterized in that, A first bearing (36) is provided between the eccentric driving pin and the reciprocating rod (1).

4. The balance mechanism according to claim 2, wherein, The balance weight assembly further includes a connecting pin (21), the connecting pin (21) is connected to the balance weight (2), and the lower end of the connecting pin (21) is inserted into the eccentric circular track groove.

5. The balance mechanism according to claim 4, characterized in that, A second bearing (22) is provided between the lower end of the connecting pin (21) and the eccentric circular track groove.

6. The balance mechanism according to claim 2, characterized in that, There is a first eccentricity between the axis center of the first driving part (32) and the axis center of the driving disk's own rotation axis (31), and a second eccentricity between the axis center of the second driving part (33) and the axis center of the driving disk's own rotation axis (31), and they satisfy: the product of the mass of the reciprocating rod and the first eccentricity is approximately equal to the product of the mass of the balance weight assembly and the second eccentricity.

7. The balance mechanism according to claim 1, wherein, The center of gravity of the driving disk coincides with the axis center of its own rotation axis.

8. The balance mechanism according to claim 7, characterized in that, The driving disk (3) is provided with weight-reducing holes (34) and / or trimming parts (35) to make the center of gravity of the driving disk coincide with the axis center of its own rotation axis.

9. The balance mechanism according to claim 1, characterized in that, It further includes: A driving element, which is connected to the driving disk to drive the driving disk to rotate around its own axis center.

10. The balance mechanism according to claim 9, characterized in that, The driving element includes a motor and a gear shaft (5), and the gear shaft (5) is connected between the motor and the driving disk (3).

11. The balance mechanism according to claim 9, characterized in that, The driving disk is configured as a first bevel gear, the driving element includes a motor and a second bevel gear (6), the second bevel gear (6) is connected between the motor and the first bevel gear, and the included angle in the axial direction between the second bevel gear (6) and the first bevel gear is less than or equal to 90°.

12. The balance mechanism according to claim 1, wherein, It further includes a housing (4). The housing has a first cavity for limiting the reciprocating rod and a second cavity (42) for limiting the balance weight, so that when the driving disk rotates around its own rotation axis, the reciprocating rod (1) and the balance weight (2) can only move in the axial direction of the reciprocating rod.

13. A reciprocating machine tool, characterized in that, It includes the balance mechanism described in any one of claims 1-12.

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