JP2004154903A - Working tool - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide technique contributing to improvement in synthetic performance such as reduction of weight, appearance and cost control while securing the vibration proof performance in the working tool. <P>SOLUTION: A dynamic vibration absorber 201 has body parts 203, 205, 207, a weight 211 stored in the body part 203, and a spring element 217 connecting the respective end parts of the weight 211 between the body parts 205, 207. This working tool controls vibration in driving a tool bit by the above absorber. The dynamic vibration absorber 201 is removably secured to the working tool body part. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a vibration control technique for a power tool such as a hammer or a hammer drill that drives a tool bit at a constant cycle.
[0002]
[Prior art]
Japanese Patent Laying-Open No. 52-109673 (Patent Document 1) discloses a configuration of a hammer provided with a vibration damping device. In this conventional hammer, an anti-vibration chamber is formed integrally with the main body housing (and the motor housing) in a region below the main body housing and in front of the motor housing, and a dynamic vibration absorber is provided in the anti-vibration chamber. Hold the container. Then, a strong vibration in the longitudinal direction of the hammer generated when the hammer is driven is absorbed by the dynamic vibration absorber.
[0003]
By the way, the above-mentioned dynamic vibration absorber needs to have an appropriate size to appropriately absorb a large vibration at the time of driving the hammer, and the capacity of the vibration isolating chamber for accommodating the dynamic vibration absorber necessarily needs to be an appropriate size. It becomes. For this reason, the above-mentioned conventional hammer has disadvantages in terms of measures for reducing the weight of the entire hammer, securing a good-looking external shape, and reducing costs, while ensuring excellent vibration damping properties.
[0004]
[Patent Document 1]
JP-A-52-109673
[Problems to be solved by the invention]
The present invention has been made in view of the above circumstances, and provides a technique that contributes to improving overall performance such as weight reduction, appearance, and cost control while ensuring vibration control of a power tool. With the goal.
[0006]
[Means for Solving the Problems]
In order to achieve the above object, the invention described in each claim is configured.
According to the first aspect of the present invention, a power tool is provided which is controlled by the dynamic vibration absorber when the tool bit is driven. The dynamic vibration absorber is a device for reducing the vibration of the vibration damping object via a weight connected to the vibration damping object via an elastic element and a damping element. The dynamic vibration absorber according to the present invention is configured to include a main body, a weight accommodated in the main body, and an elastic element that connects each end of the weight with the main body. When vibration occurs when the work tool is driven, the weight connected to the main body via the elastic element relatively opposes the vibration to take a countermeasure against vibration. It is sufficient that the weight is connected to the main body by at least an elastic element, and a configuration in which the weight is connected to the main body by a damping element is also included.
[0007]
Note that, as the “work tool” in the present invention, a hammer or a hammer drill typically corresponds to the degree of necessity of vibration damping by the dynamic vibration absorber. In addition, the electric tool or the air drive method typically corresponds to the drive type of the work tool.
[0008]
The dynamic vibration absorber according to the present invention is detachably fixed to the power tool body. Therefore, depending on the work mode and the necessity of vibration suppression, etc., the dynamic vibration absorber is fixed to the work tool body to perform vibration suppression, and the dynamic vibration absorber is removed from the work tool body to reduce the weight and slimness. It is possible to appropriately switch between a case where the work is performed using a work tool having a simple appearance. In addition, it is possible to control the cost and convenience of the work tool rationally by leaving the decision on whether or not to set the dynamic vibration absorber to the operator while securing the possibility of mounting the dynamic vibration absorber. Become.
[0009]
(Invention of claim 2)
According to the second aspect of the invention, the main body of the dynamic vibration absorber according to the first aspect has a fastening portion. The fastening portion is movable relative to the dynamic vibration absorber while receiving the elastic force of the elastic element. The dynamic vibration absorber is fixed to the power tool main body through the movement of the fixing part in a state where the elastic force of the elastic element acts. In order to fix the dynamic vibration absorber to the work tool body, the elastic element of the dynamic vibration absorber is used to exert the vibration damping action, so that the configuration of the member elements can be rationalized as much as possible. .
[0010]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In the embodiment of the present invention, an electric power hammer will be described as an example of a power tool. As shown in FIG. 1, the electric hammer 101 according to the present embodiment generally includes a main body 103 forming an outer periphery of the electric hammer 101, and a tool holder 131 connected to a distal end region of the main body 103. The hammer bit 133 is detachably attached to the tool holder 131. The hammer bit 133 corresponds to a “tool bit” in the present invention.
[0011]
The main body 103 has a motor housing 107 containing a drive motor 105, a gear housing 113 containing a motion conversion mechanism 109 and a striking element 111, and a hand grip 121 on which a trigger switch 123 is set. Although not particularly shown for the sake of convenience, the rotational output of the drive motor 105 is appropriately converted into a linear motion by the motion converting mechanism 109 and transmitted to the striking element 111, and is transmitted through the striking element 111 in the longitudinal direction of the hammer bit 133 (see FIG. 1 in the left-right direction). Further, the electric hammer 101 according to the present embodiment can be switched to a hammer drill mode in which the hammer bit 133 simultaneously performs a hammer operation in a long axis direction and a drill operation in a circumferential direction by an appropriate operator's operation. I have.
[0012]
A dynamic vibration absorber 201 is attached to an upper region of the main body 103 of the electric hammer 101 via fastening portions 141 and 141 formed in a hook shape. The detailed structure of the dynamic vibration absorber 201 is shown in FIG. An outer shell of the dynamic vibration absorber 201 includes a cylindrical body 203 formed in a long hollow shape, and fixed ends 205 and movable ends 207 attached to both ends of the cylindrical body 203, respectively. The fixed end 205 is fixedly attached to the cylindrical body 203. The movable end 207 is attached to the cylinder 203 so as to be relatively movable in the longitudinal direction of the cylinder 203 (the left-right direction in FIG. 2). The movable range of the movable end 207 relative to the cylinder 203 is defined by the relationship between the protrusion 203 a and the corner 207 b formed in the movable end 207 with respect to the hole 203 a and the corner 203 b formed in the cylinder 203. It is appropriately defined by the combination. Note that the cylindrical body 203, the fixed end 205, and the movable end 207 correspond to the "dynamic vibration absorber main body" in the present invention, and the movable end 207 corresponds to the "fastening part" in the present invention.
[0013]
A weight 211 extending in the longitudinal direction of the cylinder 203 is arranged in the cylinder 203. The weight 211 has a large-diameter portion 213 and a small-diameter portion 215, and biasing springs 217 are attached to left and right end regions of the large-diameter portion 213, respectively. The biasing spring 217 corresponds to the “elastic element” in the present invention.
[0014]
One end of the biasing spring 217L on the left side of the large diameter portion 213 of the weight 211 in the drawing is attached to the left end of the large diameter portion 213 of the weight 211, and the other end is attached to the fixed end 205. Further, the long outer peripheral portion of the small diameter portion 215 of the weight 211 is configured to be in contact with the inner periphery of the biasing spring 217L. The biasing spring 217L applies an elastic force to the weight 211 when the weight 211 moves in the long axis direction of the cylindrical body 203.
[0015]
On the other hand, the biasing spring 217R on the right side of the large diameter portion 213 of the weight 211 has one end attached to the right end of the large diameter portion 213 of the weight 211 and the other end attached to the movable end 207. Further, the long outer peripheral portion of the small diameter portion 215 of the weight 211 is configured to be in contact with the inner periphery of the biasing spring 217R. The urging spring 217R normally exerts an elastic force so that the weight 211 and the movable end 207 separate from each other. Therefore, the movable end portion 207 is always placed at the right end position of the movable range by the projection portion 207a being locked by the hole portion 203a, and is biased by the weight 211 which is to move in the long axis direction of the cylindrical body 203. When 217R exerts an elastic force, it functions as a fixed end. FIG. 2 shows this state. On the other hand, when attaching the dynamic vibration absorber 201 to the main body 103 of the electric hammer 101 as will be described later, the movable end 207 is moved to the position of the urging spring 217R (and the urging spring 217L) through manual operation by an operator. It is configured to be movable leftward in the movable range while resisting the resilience. At this time, the left movable range of the movable end 207 is defined by the corner 207b shown in FIG. 2 abutting the corner 203b of the cylindrical body 203. Note that the moving direction of the movable end 207 in this case is indicated by a symbol F in FIG.
[0016]
In addition, locking portions 209 which can be engaged with fastening portions 141 and 143 formed on the main body 103 of the electric hammer 101 shown in FIG. 1 are formed in the respective end regions of the fixed end 205 and the movable end 207. Have been.
[0017]
The operation of the electric hammer 101 configured as described above will be described. When the operator turns on the trigger switch 123 of the hand grip 121 shown in FIG. 1, the drive motor 105 is energized and driven. The rotation output of the drive motor 105 is converted into linear motion by the motion conversion mechanism 109, whereby the striking element 111 generates an impact force on the hammer bit 133, and performs a predetermined hammer operation on the workpiece. If necessary, the hammer bit 133 can be rotated in the radial direction to perform the hammer drill operation. The details of the hammer drive and hammer drill drive of the hammer bit 133 are well-known and will not be described in detail.
[0018]
As described above, the dynamic vibration absorber 201 fixed to the main body 103 has a vibration damping function against shocking and periodic vibrations generated when the hammer bit 133 is driven. That is, when the main body 103 of the electric hammer 101 is regarded as a control target body to which a predetermined external force (vibration) acts, the main body 103 serving as the control target body is controlled by the vibration damping element of the dynamic vibration absorber 201. A certain weight 211 and a biasing spring 217 cooperate to perform dynamic vibration suppression. Thereby, the vibration of the electric hammer 101 in the present embodiment is effectively suppressed. Note that the principle of vibration damping by the dynamic vibration absorber itself is a known matter, and a detailed description thereof is omitted.
[0019]
By the way, the weight of the weight 211 is appropriately determined according to the vibration damping performance as a dynamic vibration absorber. In the present embodiment, the weight 211 is formed by the large-diameter portion 213 and the small-diameter portion 215, so that the outer shape of the weight is reduced. The dimensions can be appropriately controlled, and the weight 211 can be made compact as a whole. Furthermore, the weight 211 is formed in a long shape in the moving direction, and the outer periphery of the small diameter portion 215 of the weight 211 is in close contact with the inner periphery of the biasing spring 217, so that the weight 211 When moving in the long axis direction, the operation of the weight 211 can be stabilized.
[0020]
In the dynamic vibration absorber 201 in the above embodiment, the vibration damping mechanism is configured by using the weight 211 and the urging spring 217. For example, in the cylindrical body 203, the oil is provided on both the left and right regions of the large diameter portion 213 of the weight 211. Can be set so that not only the elastic force of the elastic element but also the damping force acts on the weight 211 when the weight 211 moves within the cylindrical body 203.
[0021]
On the other hand, in the present embodiment, when it is not necessary to perform the vibration damping by the dynamic vibration absorber 201 according to the work mode or the like, the dynamic vibration absorber 207 is electrically operated by appropriately operating the movable end 207. The hammer 101 is detached from the main body 103. That is, as shown in FIG. 1, with respect to the dynamic vibration absorber 201 attached to the main body 103 of the electric hammer 101, the movable end 207 is moved toward the cylindrical body 203 while resisting the elastic force of the urging spring 217 shown in FIG. Then, the locking of the locking portion 209 to the fastening portion 143 (see FIG. 1) is released. Thereby, the dynamic vibration absorber 201 is detached from the main body 103 of the electric hammer 101. Thus, it is possible to reduce the weight of the electric hammer 101 and to secure the appearance in the appearance.
[0022]
In the present embodiment, only one end of the dynamic vibration absorber 201 is configured as the movable end 207. However, both ends of the dynamic vibration absorber 201 are configured as the movable end 207 that can contract in the direction of the cylinder 203. It is also possible. Further, when the dynamic vibration absorber 201 is detachably fastened to the main body 103 of the electric hammer 201, a fastening mode other than the mode utilizing the elastic force of the urging spring 217, for example, the cylindrical body 203 and the body 103 Various fastening forms can be adopted, such as a form in which the space is fastened with a so-called hook-and-loop fastener, and a way in which the space is fastened with a magnet.
[0023]
【The invention's effect】
ADVANTAGE OF THE INVENTION According to this invention, the technique which contributes to improving the overall performance, such as weight reduction, external appearance, and cost control, while ensuring the vibration damping property of a power tool was provided.
[Brief description of the drawings]
FIG. 1 shows the overall configuration of an electric hammer according to the present embodiment.
FIG. 2 is a sectional view showing a detailed structure of the dynamic vibration absorber according to the present embodiment.
[Explanation of symbols]
101 Electric hammer (work tool)
103 Body 105 Drive motor 107 Motor housing 109 Motion conversion mechanism 111 Striking element 113 Gear housing 121 Hand grip 123 Trigger switch 131 Tool holder part 133 Hammer bit (tool bit)
141, 143 Dynamic vibration absorber attachment part 201 Dynamic vibration absorber 203 cylindrical body (main body)
205 Fixed end 207 Movable end 209 Locking part 211 Weight 213 Large diameter part 215 Small diameter part 217 Urging spring (elastic element)

Claims (2)

A power tool having a main body, a weight accommodated in the main body, and a dynamic vibration absorber having an elastic element connecting the weight with the main body, which performs vibration suppression at the time of driving a tool bit,
The working tool, wherein the dynamic vibration absorber is detachably fixed to the working tool body. 2. The power tool according to claim 1, wherein the main body of the dynamic vibration absorber has a fastening portion that is relatively movable with respect to the main body while receiving the elastic force of the elastic element. 3. The power tool is characterized in that the dynamic vibration absorber is fixed to the power tool body via a movement of the fixing part.

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