JPS6224983A - Power tool - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field] The present invention relates to a power tool such as a hammer drill, and particularly to a case housing a drive mechanism thereof.

[Background Art] In a power tool such as this hammer drill, it is necessary to house the drive mechanism in a case and then incorporate it into the housing. As shown in Japanese Patent No. 34270, the accommodated drive PIj is divided by a cross section perpendicular to the axial direction of the tub. However, with this structure, the coupling members of each block of the case are likely to loosen due to axial vibration, and it is also difficult to replenish grease to the mechanical parts and repair parts. In order to do this, it must be divided into several blocks, which increases the cost.

[Object of the Invention] The present invention has been made in view of the above points, and its object is to provide a power tool that is easy to assemble and easy to maintain.

[Disclosure of the Invention] The present invention provides a power tool that includes a case that accommodates a drive mechanism and has an input section at one end and an output section at the other end, in which the casing is arranged in an axial direction from the input section to the output section. The case is divided into two halves along a plane parallel to the case, and the case is formed by a pair of halves.A motor mounting surface is provided on the outer surface of the input part of the case as a flat part perpendicular to the joint surface of the case, and the motor mounting surface is used to connect the cases. This device is characterized in that the screw is located near the bearing portion for the accommodated drive mechanism.

The present invention will be explained in detail below based on an embodiment of a hammer drill shown in the drawings. The housing 1 has a chuck part 41 on its front end to which the bit 38 is attached, and the rear underground part is a grip 3, and in front of this grip 3, a storage battery 5 is stored via a handle space 52. A chamber 50 is integrally provided, and an auxiliary grip 4 is attached to the lower front end. In the figure, 12 is a switch, and 11 is a switch handle, which can be operated with the hand holding the grip 3. A storage battery 5 housed in a storage chamber 50 whose front face is a lid 51 has a terminal 55 installed on the upper surface of its rear end brought into contact with a contact spring 56 arranged inside the housing 1.

The soter 2 is housed in the rear end of the housing 1 together with a control circuit box 13 with its axial direction being the front-back direction, and a pinion 21 is attached to its output shaft 20. This pinion 21 is rotatably supported at both ends by bearings 45, 45 in the case 6, and meshes with a gear 22 of an intermediate shaft 23-@ whose axial direction is parallel to the axial direction of the motor 2. Further, the intermediate shaft 23 is equipped with a pinion 24 at the other end, and a bevel gear 26 is freely rotatably attached to the intermediate shaft 23. Furthermore, the intermediate shaft 23 is spline-coupled to the intermediate shaft 23 at the center and is engaged by a clutch spring 44. A biased clutch plate 43 is attached to the bevel gear 26 side. The clutch plate 43 is the third
The engagement with the bevel gear 26 is controlled according to the operation of the clutch switching lever 49 shown in the figure.

At the front of the motor 2 in the axial direction, both front and rear ends are bearings 46.
A cylindrical cylinder 31, which is supported by the motor 46 and can freely rotate around the pongee, is installed coaxially with the motor 2.
has been done. This cylinder 31 has a gear 25 fixed to the outer periphery of its rear end that engages with the above-mentioned union 24, and also houses a hammer 33 in its front part and a piston 32 in its rear part. The space between the two is used as an air spring chamber. A crankshaft 28 is installed between the cylinder 31 and the motor 2 and is rotatably supported by bearings 47 and 47 with the axial direction being the vertical direction, and a connecting rod 30 whose one end is connected to the piston 32. The other end is connected to this crankshaft 28 by a crank pin 29,
Further, a bevel gear 27 that meshes with the bevel gear 26 is provided at the lower end of the crankshaft 28. The rotation of the crankshaft 28 causes the piston 32 to reciprocate and drive the hammer 33 via an air spring.

The rotation of the cylinder 31 is caused by a spindle 34, and the reciprocation of the piston 32 is caused by a hammer 33 and a striker 35.
is transmitted to bit 38 via.

The spindle 34 has a cylindrical shape with a rear end fixed to the front end of the cylinder 31 by a stop key 37, and supports a striker 35 slidably in the axial direction in the rear end. A dustproof ring 48 is attached. Note that the sliding movement of the striker 35 is similar to that of the striker 35.
The range is regulated by the engagement of the stop key 37 with the axially long long groove 36 formed in the stop key 37.

The bit 38 is held with its rear end contained within the front part of the spindle 34. By engaging a long groove 39 extending in the axial direction provided on the outer circumferential surface of the rear end of the pit 38 with a key 40 held by the spindle 34, it is possible to freely slide in the axial direction within a predetermined range. At the same time, the bit 38 is rotated together with the spindle 34. The bit 38 is attached and detached by retracting the chuck portion 41 against the coil spring 42 so that the key 40 can be moved outward.

However, in this lever hammer drill, when the motor 2 is rotated, the bit 38 receives rotational force from the intermediate shaft 23 via the cylinder 31 and spindle 34 and rotates. Further, when the clutch formed by the clutch plate 43 and the bevel gear 26 is connected, the hammer 33 follows the reciprocating movement of the piston 32 caused by the crankshaft 28 and the connecting rod 30, and the hammer 33 hits the striker 35. *i* is transmitted to the rotating cutter 38 via the striker 35.

Now, in case 6, as shown in Fig. 2 and below, the output shaft 20, cylinder 31, or intermediate shaft 23 of the output shaft 2 is divided into two by a plane parallel to the axial direction, and a pair of half-rear 6
1.62, and both halves 61
, 62. The motor 2 is attached to a flat surface 63 extending between both halves 61 and 62, which is provided on the rear end surface orthogonal to the joining surfaces of the two halves 61 and 62. Further, the two halves 61 and 62 constituting the case 6 are connected by a plurality of screws 64 in a direction perpendicular to the axial direction. Here, the screw 64 for connection is attached to the portion shown by A in FIG. 1, that is, the bearings 45, 46, .
47 and at approximately equal intervals along the outer shape of the case 6. Grease, etc. filled in the case 6 to lubricate the drive mechanism is applied to both halves 61.
In order to prevent leakage from the joint surfaces of the joints 62, the joint surfaces are tightened so that the force is approximately equal at each part. In this case, by providing 7 runs 65, 65 along the joint surface on each half 61° 62 as shown in the illustrated example, grease leakage can be further reliably prevented, and the liquid packing can be It would be even better if it was applied to the joint surfaces of the lunges 65.65.

Further, the case 6 is fixed to the housing 1 by l) fixing the 7 langes 65 of the case 6 to the bosses 16 provided on the housing 1 at three locations indicated by B in FIG. 1 with screws 66. do. A plane is defined by the tip surfaces or step surfaces of the three posts 16, and by bringing these bosses 16 into contact with the seven runs 65, the case 6 is positioned and securely fixed at the same time. be.

Furthermore, in this case 6, the backlash i1 of the meshing of the bevel gears 26°27 mentioned above is present! ! It has a built-in adjustment mechanism. This adjustment mechanism consists of a 7I4 set screw 71 that contacts the rear end surface of the intermediate shaft 23, a front end surface of the intermediate shaft 23, and a case 6.
The spring 72 is located between the inner surface and presses the intermediate shaft 23 toward the adjustment screw 71. By turning the adjustment screw 71 screwed into the case 6, the intermediate shaft 23 can be moved in the axial direction. is adjusted by moving the bevel gear 26 in the axial direction gJ. This allows the backlash adjustment to be performed after the drive mechanism has been assembled into the case 6.

[Effects of the Invention] As described above, in the present invention, since the case is divided into two along a plane parallel to the axial direction extending from the input section to the output section, it is easy to grease and repair the drive mechanism. At the same time, since the connecting direction of the pair of half-holes is perpendicular to the axial direction, loosening is less likely to occur due to axial vibration of the drive mechanism, and furthermore, the motor mounting surface is a flat part perpendicular to the joint surface of the case. In addition, the motor can be easily fixed and positioned, the meshing precision of the gear train for rotation transmission can be increased, and vibration and noise can be reduced. Since the mounting screw is located near the bearing for the drive fi mechanism, the drive mechanism can be supported reliably without rattling, and in this respect as well, vibration and noise are low. It is something that can be done.

[Brief explanation of the drawing]

Figure 11 is a longitudinal sectional view of one embodiment of the present invention, Figure fjrJ2 is a sectional view taken along line X-X1 of the same, Figure tjS3 is a sectional view taken along line Y-Y of the same, and Figure 4 is a perspective view of the case of the same. 1 is the housing, 2 is the motor, 6 is the case, 61° 62 is the half body,
64 is the agent showing the screw Patent attorney Stone 1)' length 7 Figure 2 Figure 3 b

Claims (2)

[Claims] (1) In a power tool equipped with a case that houses a drive mechanism and has an input section at one end and an output section at the other end, the case is divided into two along a plane parallel to the axial direction from the input section to the output section. A case is formed by a pair of halves, and a motor mounting surface is provided on the outer surface of the input part of the case as a flat part perpendicular to the joint surface of the case, and the mounting position of the coupling screw of the case is adjusted. A power tool characterized in that the power tool is formed near a bearing part for a drive mechanism. (2) The power tool according to claim 1, wherein the two halves of the case are connected by screws arranged at approximately equal intervals.