JP3727474B2 - Vibration prevention mechanism and machine tool provided with vibration prevention mechanism - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a vibration preventing mechanism for preventing vibration generated on both rotating shafts in a machine that transmits rotation of a driving shaft to a driven shaft by a gear mechanism.
[0002]
[Prior art]
2. Description of the Related Art Conventionally, in a machine that transmits the rotation of a drive shaft to a driven shaft by a gear mechanism, vibrations are generated on both rotary shafts due to gear backlash and the like. As a vibration preventing mechanism for preventing such vibration, a mechanism described in JP-A-63-123602 is known.
In such an apparatus, one end of the rotating shaft is extended, and a positive displacement rotary pump is attached to the end. The positive displacement rotary pump is provided with a suction pipe for sucking oil in the tank and a protruding pipe for returning the oil sucked into the positive displacement rotary pump into the tank.
In such an apparatus, vibration energy of the rotary shaft is converted into energy for compressing oil of a positive displacement rotary pump attached to one end of the rotary shaft, and therefore vibration of the rotary shaft is attenuated and prevented.
[0003]
[Problems to be solved by the invention]
However, the vibration preventing mechanism described above has a problem in that the rotary shaft is extended and the positive displacement rotary pump is attached to one end thereof, so that the rotary shaft becomes long and the apparatus becomes large.
[0004]
[Means for Solving the Problems]
Therefore, in order to solve the above-described problems, the invention is set forth as described in each claim .
According to the vibration preventing mechanism of the first aspect of the invention, when the drive shaft rotates, the rotation is transmitted to the driven shaft by the gear mechanism, and the driven shaft rotates. Since the gear mechanism is wrapped in the first casing, it also functions as a gear pump. The oil mechanism sucks oil into the compression chamber in the first casing through the oil chamber , compresses the oil chamber through the oil discharge port, and compresses the oil chamber. To discharge. Therefore, the compression action of the gear pump acts as a rotational resistance on the drive shaft and the driven shaft, and vibrations generated on the drive shaft and the driven shaft are attenuated and prevented. At this time, the resistance added to the drive shaft and the driven shaft can be adjusted by adjusting the circulating oil flow rate with the flow rate adjusting mechanism. In addition, according to the vibration preventing mechanism, the gear mechanism that is necessarily required to transmit the rotation of the drive shaft to the driven shaft is wrapped in the first casing so as to function as a gear pump. Therefore, it is not necessary to attach a positive displacement rotary pump by extending the shaft, and the apparatus can be miniaturized.
[0005]
Further , according to the present invention , the first casing is arranged so that the oil suction port is located at a position lower than the liquid level of the oil chamber formed in the second casing. Oil in the oil chamber is sucked from the suction port, compressed in the compression chamber, and discharged to the oil chamber from the oil discharge port. Therefore, the oil chamber can play the role of an oil passage and an oil reservoir that communicate the oil inlet and the oil outlet.
[0006]
According to the machine tool of the invention of claim 3, when the drive shaft rotates, the rotation is transmitted to the driven shaft by the gear mechanism, and the driven shaft and the tool rotate. Since the gear mechanism also functions as a gear pump, the compression action of the gear pump acts as a rotational resistance on the drive shaft and the driven shaft. For this reason, the vibration generated in the driven shaft by the cutting resistance acting on the tool is attenuated and prevented. Therefore, processing accuracy can be improved. Further, since the gear mechanism also functions as a gear pump, it is not necessary to extend the shaft and attach a positive displacement rotary pump, and the machine tool can be downsized.
[0007]
DETAILED DESCRIPTION OF THE INVENTION
The outline of the vibration preventing mechanism of the present invention will be described with reference to FIG. FIG. 1 is a drawing for explaining the configuration of the vibration preventing mechanism of the present invention.
As shown in FIG. 1, the vibration preventing mechanism of the present invention is applied to a machine having a drive shaft 5a and a driven shaft 5b and transmitting the rotation of the drive shaft 5a to the driven shaft 5b by a gear mechanism (gears 4a, 4b). The For example, it can be applied to a machine tool such as a lathe or a milling machine. Moreover, it can be applied not only to a machine tool but also to a power transmission mechanism of an elevator such as an elevator.
[0008]
In such a machine, the gear mechanism (4a, 4b) for transmitting power is configured to be wrapped in a casing 6 and also function as a gear pump. The casing 6 is formed with an oil suction port 6b for sucking oil into the gear pump and an oil discharge port 6a for discharging oil from the gear pump. The oil discharge port 6a communicates with the oil reservoir 9 via the oil discharge passage 7a, and the oil reservoir 9 communicates with the oil intake port 6b via the oil suction passage 7b. The oil discharge passage 7a is provided with an oil flow rate adjusting mechanism 8 that adjusts an oil flow rate (oil circulation flow rate) flowing through the oil discharge passage 7a (oil suction passage 7b). The oil flow rate adjusting mechanism 8 can be configured as a channel area adjusting means for adjusting the channel cross-sectional area of the oil channel 7a such as an orifice or a throttle valve. Further, the oil flow rate adjusting mechanism 8 may be configured to return the oil in the oil reservoir 9 to the oil discharge passage 7a with a pump, for example. In this way, the circulating oil flow rate can be adjusted by changing the output of the pump, and the oil circulation amount can be controlled more flexibly than by the flow path area adjusting means.
[0009]
In the vibration preventing mechanism configured as described above, when the drive shaft 5a rotates, the driven shaft 5b rotates and the gears 4a and 4b also rotate. Since the gears 4a and 4b rotate, the oil in the oil reservoir 9 is sucked into the casing 6 through the oil suction passage 7b. The oil sucked into the casing 6 is compressed, discharged from the oil discharge port 6a to the oil discharge passage 7a, and returned to the oil reservoir 9. The force acting when the oil is compressed in the casing 6 becomes the rotational resistance of the drive shaft 5a and the driven shaft 5b, and attenuates and prevents the vibration generated in the drive shaft 5a and the driven shaft 5b. This rotational resistance can be changed by adjusting the oil flow rate circulated by the oil flow rate adjusting mechanism 8.
[0010]
Next, an embodiment in which the vibration preventing mechanism according to the present invention is applied to a circular saw will be described with reference to FIGS.
FIG. 2 is a perspective view showing a schematic configuration of the circular saw machine, and FIG. 3 is a view of only the main body 10 of the circular saw machine shown in FIG. 2 as viewed from the side, before cutting the workpiece. FIG. 4 is a view similar to FIG. 3 and shows a state after the workpiece has been cut, and FIG. 5 is a power transmission mechanism disposed in the casing of the circular saw machine shown in FIG. FIG. 6 is a diagram showing the configuration of the vibration preventing mechanism of the present invention disposed in the casing of the circular saw machine shown in FIG. 2.
[0011]
As shown in FIG. 2, the circular saw machine 1 provided with the vibration preventing mechanism of the present invention includes side frames 2 a and 2 b, a main body 10 that is rotatably attached to the side frames 2 a and 2 b, and the main body 10 rotates. And a bracket 5 which can be attached. The side frames 2a and 2b are provided with vise portions (not shown) so that the workpiece 90 is fixed.
[0012]
The main body 10 of the circular saw machine 1 has a second casing 50 as shown in FIG. 3, and the second casing 50 is attached to the side frames 2 a and 2 b so as to be rotatable at a fulcrum 54. In addition, the cylinder 56 is rotatably attached to the second casing 50 at the cylinder connecting portion 52, and the tip of the cylinder rod 58 of the cylinder 56 is rotatably attached to the bracket 5 by the rod connecting portion 60. It is done. For this reason, when the cylinder rod 58 of the cylinder 56 is contracted from the state in which the cylinder rod 58 of the cylinder 56 is extended (the state in FIG. 3: the state before cutting the workpiece), the main body 10 rotates around the fulcrum 54. 4 (the state in which the workpiece is cut).
The work 90 is fixed to the vise portions of the side frames 2a and 2b, and is fixed to the position shown in the drawing.
[0013]
The electric motor 12 is installed on the second casing 50, the transmission belt 16 is hung between the drive shaft 14 of the electric motor 12 and the pulley 18, and the rotation of the drive shaft 14 of the electric motor 12 is transmitted to the pulley 18. Like that. Since the pulley 18 is fitted and fixed to the shaft 19, the pulley 18 and the shaft 19 rotate at the same rotational speed. The rotation of the shaft 19 is transmitted to the shaft 24 by a power transmission mechanism 20 disposed in a second casing 50 described later. A circular saw 70 is detachably attached to the shaft 24, and the workpiece 90 is cut by rotating the circular saw 70 by the rotation transmitted to the shaft 24.
[0014]
Next, the configuration of the power transmission mechanism 20 will be described with reference to FIG. Note that the three shafts 19, 22, and 24 shown in FIG. 5 do not exist on the same plane because of the space in the second casing 50, and are arranged as shown in FIG. However, in FIG. 6, for convenience, the three shafts 19, 22, and 24 are illustrated as being on the same plane. That is, the cross section cut along the line BB in FIG.
The shaft 19 is rotatably supported by the second casing 50 by bearings 21a and 21b. An oil wheel 30 is attached to one end of the shaft 19, and a gear 26 is attached between the bearing 21a and the bearing 21b. The gear 26 meshes with a gear 27 attached to the shaft 22 so that the rotation of the shaft 19 is transmitted to the shaft 22.
The shaft 22 is rotatably supported by the second casing 50 by bearings 23a, 23b, and 23c. A gear 28 is attached to the shaft 22 between the bearing 23b and the bearing 23c. The gear 28 meshes with a gear 29 attached to the shaft 24 so that the rotation of the shaft 22 is transmitted to the shaft 24. The shaft 24 is rotatably supported by the second casing 50 by bearings 25a and 25b.
Further, the gaps between the shafts 19, 22, 24 and the second casing 50 are closed by the lids 32, 34, 36, respectively, so that the oil in the second casing 50 does not leak to the outside.
[0015]
Next, based on FIG. 6, the structure of the vibration preventing mechanism installed in the second casing 50 will be described. FIG. 6 is a cross-sectional view taken along line AA shown in FIG. An oil chamber 42 in which oil 48 is stored is formed in the second casing 50. The first casing 40 is disposed so that the oil suction port 43 and the oil discharge port 44 are positioned at a position lower than the level of the oil 48 in the oil chamber 42. A compression chamber 47 is formed in the first casing 40, and a gear 28 attached to the shaft 22 and a gear 29 attached to the shaft 24 meshing with the gear 28 are accommodated in the compression chamber 47. The first casing 40 is formed with a suction passage 45 for sucking oil 48 in the oil chamber 42 into the compression chamber 47 and a discharge passage 46 for discharging oil from the compression chamber 47 into the oil chamber 42.
The discharge passage 46 is provided with flow passage area adjusting means (not shown) for adjusting the flow passage area of the discharge passage 46. Providing such adjusting means can adjust the flow rate of oil discharged from the compression chamber 47. Further, the pressure difference between the suction port 43 and the discharge port 44 is increased by the amount of pressure loss lost by the adjusting means, and the resistance applied to the shaft 24 and the shaft 22 is increased in proportion to the pressure difference. Therefore, the resistance force applied to the shafts 22 and 24 can be adjusted by this adjusting means.
An orifice or the like can be used as the adjusting means disposed in the discharge passage 46. Moreover, what provided the weir which protrudes in the discharge channel | path 46, and was able to adjust the protrusion amount of this weir with a plunger etc. can also be used. If such a thing is used, the resistance force which acts on the axis | shaft 24 according to the rotation speed (and / or vibration) of the axis | shaft 24 can be controlled. For example, a sensor (position, speed, etc.) for detecting vibration is attached to the shaft 24, and the plunger is operated based on the signal to control the resistance force applied to the shaft 24.
[0016]
The operation of the circular saw machine having the vibration preventing mechanism will be described.
First, with the cylinder rod 58 of the cylinder 56 extended (the state shown in FIG. 3), the workpiece 90 is fixed to the vise portions of the side frames 2a and 2b. Next, when the switch of the electric motor 12 is turned on and energized, the electric motor 12 rotates and the drive shaft 14 rotates. The rotation of the drive shaft 14 is transmitted to the pulley 18 by the transmission belt 16, and the shaft 19 rotates. The rotation of the shaft 19 is transmitted to the shaft 24 by the power transmission mechanism 20 described above, and the circular saw 70 attached to the shaft 24 rotates. If the cylinder rod 58 of the cylinder 56 is gradually contracted while the circular saw 70 is rotating, the circular saw 70 hits the workpiece 90 and cutting (cutting) of the workpiece 90 is started. Then, when the cylinder rod 58 of the cylinder 56 is completely contracted (state shown in FIG. 4), the cutting of the workpiece is finished.
[0017]
Here, when the circular saw 70 hits the workpiece 90, a cutting resistance force acts on the circular saw 70 from the workpiece 90. In particular, in a cutting tool such as the circular saw 70, since the saw blade formed in the circular saw 70 periodically hits the workpiece 90 in accordance with the rotation of the circular saw 70, the cutting resistance force changes periodically. When this frequency matches the natural frequency of the shaft, a large vibration is generated, which greatly affects the surface properties and machining accuracy of the workpiece. Therefore, it is necessary to provide the shaft 24 with a resistance for reducing this vibration. In the present invention, the vibration preventing mechanism shown in FIG.
The operation of the vibration preventing mechanism of the present invention will be described with reference to FIGS.
When the shaft 22 rotates and the gear 28 attached to the shaft 22 rotates, the gear 29 that meshes with the gear 28 rotates. Since the gear 28 and the gear 29 are accommodated in the compression chamber 47, the oil 48 filled in the oil chamber 42 is sucked into the compression chamber 47 from the suction port 43 through the suction passage 45. The oil sucked into the compression chamber 47 is compressed by the rotation of the gear 28 and the gear 29, carried to the discharge passage 46, and discharged into the oil chamber 42 from the discharge port 44. At this time, the oil sucked into the compression chamber 47 acts as a rotational resistance between the shafts 22 and 24 and attenuates vibrations generated on the shafts 22 and 24. Further, the rotational resistance acting on the shafts 22 and 24 can be adjusted by the flow path area adjusting means provided in the discharge passage 46.
The oil wheel 30 is rotated in the oil 48 stored in the oil chamber 42 so that the whole oil is agitated. Only a part of the oil in the oil chamber 42 is sucked into the suction passage 45, the compression chamber 47, and the discharge passage 46. Is not circulating. As a result, only a part of the oil circulates to prevent a decrease in viscous resistance due to a temperature rise.
[0018]
As described above, in the vibration preventing mechanism of the circular saw machine shown in FIG. 2, the gear mechanism (gear 28, gear 29) required for transmitting the rotation of the shaft 22 to the shaft 24 is formed by the first casing 40. The wrapping also functions as a gear (positive displacement) pump, preventing vibration generated in the shaft 24. Therefore, unlike the prior art, it is not necessary to extend the shaft 24 outside the second casing 50 and attach a positive displacement pump, and the main body 10 can be made small.
Further, since the vibration of the shaft 24 can be prevented, the vibration of the circular saw 70 attached to the shaft 24 can also be prevented, and the processing accuracy and the property of the processing surface can be improved.
Further, since the first casing 40 is arranged at a position lower than the oil level of the oil chamber 42 formed in the second casing 50, an oil passage and an oil communicating the suction port 43 and the discharge port 44 of the first casing 40 are provided. It is not necessary to provide an oil reservoir provided in the passage, and the apparatus itself can be simply configured. In addition, when updating equipment such as adding an anti-vibration device to existing equipment, it is only necessary to replace the main body 10 and the existing equipment can be used effectively.
The resistance force acting on the shaft 24 can be adjusted by appropriately changing the viscosity of the oil 48 or by the flow channel area adjusting means provided in the discharge passage 46.
[0019]
【The invention's effect】
As described above in detail, the vibration preventing mechanism according to the present invention wraps the gear mechanism required for transmitting the rotation of the drive shaft in the first casing, so that this portion can be used as a positive displacement rotary pump. In order to function, it is not necessary to extend the shaft and attach a separate positive displacement rotary pump, and the apparatus can be miniaturized.
[Brief description of the drawings]
FIG. 1 is a view for explaining the configuration of a vibration preventing mechanism according to the present invention.
FIG. 2 is a perspective view of a circular saw machine equipped with a vibration preventing mechanism according to an embodiment of the present invention.
FIG. 3 is a side view of the main body of the circular saw machine shown in FIG. 2 and shows a state before the workpiece is cut.
4 is a side view of the main body of the circular saw machine shown in FIG. 3, and shows a state after a workpiece has been cut. FIG.
5 is a view for explaining a configuration of a power transmission mechanism arranged in a casing of a main body of the circular saw machine shown in FIG. 2;
6 is a view showing a configuration of a vibration preventing mechanism arranged in a casing of a main body of the circular saw machine shown in FIG. 2;
[Explanation of symbols]
10..Main body 12..Electric motor 16..Transmission belt 19..Shaft 22..Shaft 24..Shaft 26..Gear 27..Gear 28..Gear 29..Gear 40..First casing 42. -Oil chamber 45-Suction passage 46-Discharge passage 47-Pressure chamber 50-Second casing 56-Cylinder 70-Circular saw

Claims (3)

A drive shaft; a driven shaft to which the rotation of the drive shaft is transmitted; a gear mechanism for transmitting the rotation of the drive shaft to the driven shaft; and a compression chamber formed by wrapping the gear mechanism; A first casing for causing the mechanism to function as a gear pump; a second casing for enclosing the first casing to form an oil chamber; and the first chamber for communicating the oil chamber and the compression chamber. An oil suction port formed in the casing and an oil discharge port, wherein the first casing is disposed so that the oil suction port is positioned lower than the oil level in the oil chamber, and the oil suction port The oil sucked from the mouth is discharged from the oil discharge port, and the oil passes through the oil chamber and is returned to the oil suction port. Vibration prevention mechanism flow rate adjustment mechanism is provided between the compression chamber. The vibration preventing mechanism according to claim 1,
Wherein a position lower than the oil level in the oil chamber, said so that the compression chamber and the oil suction port and said oil discharge port is positioned first casing arranged vibration preventing mechanism. A drive source, a drive shaft to which rotation of the drive source is transmitted, a driven shaft to which rotation of the drive shaft is transmitted, a tool attached to the driven shaft, and rotation of the drive shaft to the driven shaft A gear mechanism for transmitting, a compression chamber is formed by enclosing the gear mechanism, a first casing for functioning the gear mechanism as a gear pump, and an oil chamber is formed by enclosing the first casing. An oil suction port and an oil discharge port of a compression chamber formed in the first casing communicating with the second casing, the oil chamber and the compression chamber, and an oil in an oil reservoir of the oil chamber It said first casing are arranged such that the oil suction port at a position lower than the liquid surface is positioned, the oil sucked from the oil suction port is discharged from the oil discharge port, the oil The oil chamber has a configuration is returned to the oil suction port through, and machine tool flow rate adjustment mechanism is provided between the compression chamber and the oil discharge port.

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