JP3924497B2 - Dial gauge - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a dial gauge.
[0002]
[Background]
As a general dial gauge, a pointer-type dial gauge that displays a displacement amount of a spindle by a rotation angle of the pointer and a digital-type dial gauge that digitally displays a displacement amount of the spindle are known.
The pointer-type dial gauge includes a case main body, a spindle that is slidably supported in the axial direction through the outer peripheral wall of the case main body, and a power transmission mechanism that transmits the sliding amount of the spindle to the rotation angle of the pointer. It is configured with.
The case body includes a bush as a bearing that slides and guides the spindle in the axial direction. The power transmission member is a gear train provided with a rack and pinion or the like.
On the other hand, the digital dial gauge includes, instead of the power transmission mechanism, a capacitance encoder that detects the amount of sliding of the spindle, and an electric circuit that performs arithmetic processing on the detected value of the encoder.
[0003]
In such a dial gauge manufacturing process, the case main body is formed by zinc casting, and separately from this, the bush is formed of a material having good slidability and wear resistance, such as brass. Furthermore, the bush is assembled to the case body. The spindle is formed by cylindrical grinding.
[0004]
[Problems to be solved by the invention]
However, since the case main body and the bush are separately formed and assembled, an increase in the number of parts and an increase in the assembly process cannot be avoided, leading to a reduction in manufacturing efficiency and an increase in cost.
Machining the metal into the desired form requires tremendous time and money. Furthermore, in order to improve the slidability of the spindle and the bush, the finish of the sliding surface must be made precise by processing such as lapping. Since such precision processing is required, there is a problem that the production line is complicated and expensive.
[0005]
There is still a problem of wear due to repeated sliding between the bush and the spindle. When a lubricant or the like is used between the spindle and the bush, there is a problem that dust easily adheres.
If the spindle is made of metal, such as stainless steel, and the weight increases, there is a problem that the measurement object and the spindle are deformed by a load, leading to a measurement error.
In order to maintain the measurement accuracy, it is necessary to keep the linear expansion of the components of the dial gauge including the spindle within a certain range. Therefore, conventionally, errors due to linear expansion are suppressed by, for example, limiting the temperature to 20 ± 10 degrees as a measurement condition. However, there is a problem that a measurement error occurs in a severe measurement environment such as a high temperature or a low temperature.
[0006]
A gear used for the power transmission member needs to maintain a certain rigidity, and therefore needs a certain thickness and size. Therefore, there is a problem that it is difficult to reduce the size of the dial gauge itself.
In the case of a digital dial gauge, there arises a problem that an internal electric circuit is malfunctioned or damaged by a surrounding magnetic field and electric field.
[0007]
An object of the present invention is to provide a dial gauge that solves the conventional problems, can be easily manufactured, has improved measurement accuracy, and has a long service life.
[0008]
[Means for Solving the Problems]
In order to achieve the above object, a dial gauge according to the present invention includes a case main body provided with an electric circuit therein, a spindle, and a bearing portion provided in the case main body and slidably supporting the spindle in the axial direction. wherein the case body and the bearing portion is integrally molded by synthetic resin containing nanoscale materials, the case body is characterized Rukoto which have a conductivity.
[0009]
In general, synthetic resins are fragile and have a high linear expansion coefficient. However, adding a nanoscale material (for example, carbon nanofiber) to a synthetic resin base material (for example, polystyrene) enhances rigidity and suppresses linear expansion. Effects such as improved wear resistance, reduced friction coefficient, and improved thermal conductivity can be obtained. Furthermore, by adding a nanoscale substance and appropriately setting various conditions, it is possible to impart conductivity or insulation to the synthetic resin. The reason for this is not exactly known, but is believed to be based on nanoscale materials building networks within the synthetic resin.
[0010]
Therefore, a bearing part can be formed with the synthetic resin containing a nanoscale substance. Furthermore, the number of parts required for assembling the dial gauge can be reduced by integrally molding the bearing portion together with the case body. Therefore, the manufacturing process of the case body and the bearing portion is simplified, and the cost can be reduced.
Since the case body and the bearing portion formed of a synthetic resin containing a nanoscale material have a small linear expansion coefficient, errors due to linear expansion can be eliminated. Since the coefficient of linear expansion is small, precise measurement can be performed under severe conditions such as high and low temperatures without being limited by the measurement temperature. For example, if the linear expansion of the bearing portion is reduced, the sliding of the spindle can always be guided accurately.
[0011]
Since the friction coefficient is small, the slidability is good and the spindle and the bearing can be smoothly slid without a lubricant. Therefore, it can be made difficult to get dirt and dust. Since the wear resistance performance is improved, the measurement accuracy can be maintained without being worn by repeated sliding of the bearing portion and the spindle.
Since the rigidity is reinforced, the case body can be made thinner and smaller.
Since it is a synthetic resin, the case body can be made light and the weight of the dial gauge itself can be reduced. Therefore, the convenience of handling such as carrying around and setting a dial gauge on the stand is improved.
Because it is a synthetic resin, it is more familiar to the hand than metal and there is no worry about metal allergies.
[0012]
The case body can be made conductive by a synthetic resin containing a nanoscale material. Then, when an electric circuit is provided in the case body with a digital display type dial gauge, the case body functions as a magnetic shield and can protect the internal electric circuit. Therefore, malfunction or breakage of the electric circuit can be prevented, and as a result, measurement accuracy can be improved.
[0013]
The case main body and the bearing portion are preferably formed by injection molding.
[0014]
By molding by injection molding, since machining is not required, it can be easily manufactured. Therefore, the production line and the manufacturing process can be simplified, and the cost can be reduced. Synthetic resins containing nanoscale materials have excellent molding performance, good transferability from the mold, and precise molding is possible even with injection molding. Since the mold transferability is good, there is no need to process the surface of the bearing after injection molding.
[0015]
The spindle is preferably formed by injection molding of a synthetic resin containing a nanoscale material.
[0016]
In this way, the spindle is made of a synthetic resin containing a nanoscale material, so that the spindle has enhanced rigidity, suppression of linear expansion, improved wear resistance, reduced friction coefficient, improved thermal conductivity, etc. An effect is obtained.
Since the weight can be reduced by using synthetic resin while strengthening the rigidity, the spindle and the object to be measured are not deformed by the load when the spindle is brought into contact with the object to be measured, and the measurement accuracy is improved. be able to.
By improving the wear resistance and reducing the friction coefficient, it is possible to smoothly slide between the spindle and the bearing portion without a lubricant, and to extend the service life.
Since the linear expansion coefficient is small, thermal expansion of the spindle can be suppressed, and precise measurement can be performed even under severe measurement conditions such as high temperature or low temperature.
[0017]
Since the mold transferability is good, the spindle can be precisely formed by injection molding, and grinding or surface finishing is not required after injection molding. Therefore, a manufacturing process can be simplified and cost reduction can be achieved.
[0018]
In the case of a digital display type dial gauge, in the dial gauge provided with a spindle that is slidably supported in the axial direction on the case body, the spindle has alternating conductive and non-conductive parts formed along the axial direction. Preferably, the scale has an electrode pattern, and the scale is formed by injection molding of a synthetic resin containing a nanoscale material.
[0019]
By adding a nanoscale substance and appropriately setting various conditions, the synthetic resin can be provided with conductivity or insulation. Therefore, for example, after the spindle is injection-molded as an insulator with a synthetic resin containing a nanoscale substance, a conductive electrode may be further formed with a synthetic resin containing a nanoscale substance. Then, a scale can be manufactured simply and at low cost. Compared to the case where a scale formed separately from the spindle is pasted, if the scale is provided directly on the spindle, the electrode will not peel off or the electrode will be warped. Can do.
[0020]
When the case main body includes a power transmission member that transmits the displacement movement of the spindle therein, the power transmission member is preferably formed by injection molding of a synthetic resin containing a nanoscale substance.
[0021]
As the power transmission member, for example, a rack, a gear train, or the like is formed of a synthetic resin containing a nanoscale material, thereby improving the rigidity and wear resistance of the power transmission member. Therefore, it can be set as the power transmission member which can endure repeated use. Since the rigidity is enhanced, the power transmission member can be reduced in size and thickness while maintaining the rigidity. As a result, the dial gauge itself can be reduced in size and weight.
If it is injection molding, the molding is simple, and the cost can be reduced by simplifying the manufacturing process.
[0022]
In the above, the nanoscale material is preferably any one of carbon nanoscale materials typified by carbon nanofibers or carbon nanotubes.
[0023]
The carbon nanoscale material means a nanoscale material composed of carbon atoms such as carbon nanotubes and fullerenes, typically carbon nanofibers. When such a carbon nanoscale material is added to a base material such as a synthetic resin (for example, polystyrene), such as reinforcement of rigidity, suppression of linear expansion, improvement of wear resistance performance, reduction of friction coefficient, improvement of thermal conductivity, etc. An effect is obtained. In addition, conductivity and insulation can be imparted. Therefore, the dial gauge performance can be improved by forming dial gauge components such as a case main body, a bearing portion, and a spindle using a synthetic resin containing such a carbon nanoscale substance. . Since it is a synthetic resin, it can be molded by injection molding. As a result, the manufacturing process can be simplified and the cost can be reduced.
[0024]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described together with illustrated examples.
(First embodiment)
FIG. 1 shows a pointer-type dial gauge as the dial gauge of the present invention. FIG. 1 is a diagram with the back cover of the dial gauge removed.
The dial gauge 1 includes a case body 11, a spindle 12 that passes through the outer peripheral wall of the case body 11 and is supported so as to be axially slidable, a power transmission unit 13 that transmits the displacement of the spindle 12, A display unit (not shown) for displaying the power transmitted by the power transmission unit 13 as a displacement amount of the spindle 12 is provided.
[0025]
The case main body 11 has a short cylindrical shape having a space inside, and a cylindrical stem 111 protruding downward in FIG. 1 is provided on the outer surface. A through hole through which the spindle 12 slides is formed on the outer side surface, and this through hole serves as a bearing portion 112 that slides and guides the shaft of the spindle 12. The case body 11 includes a bearing portion 112 and a stem 111, and is integrally formed of a synthetic resin including carbon nanofibers. This molding is by injection molding.
[0026]
The spindle 12 includes a rack 121 provided along the axial direction, and a contact portion 122 screwed to the tip. The spindle 12 is integrally formed of a synthetic resin including carbon nanofibers including the rack 121. This molding is by injection molding.
[0027]
The power transmission unit 13 includes a gear train as a power transmission member that transmits power from the rack 121 of the spindle 12. The gear train includes a pinion 131 meshed with the rack 121 of the spindle 12, a large gear 132 that rotates integrally with the pinion 131, a pointer shaft 133 that meshes with the large gear 132 and rotates the pointer 141 of the display unit, A backlash prevention gear 134 that meshes with the shaft 133 to prevent backlash is provided. Each gear of this gear train is formed of a synthetic resin containing carbon nanofibers. This formation is by injection molding.
[0028]
According to such a dial gauge 1, the following effects can be obtained.
(1) Since the case body 11, the spindle 12, and the power transmission unit 13 are formed of synthetic resin including carbon nanofibers, the rigidity is enhanced, the linear expansion coefficient is small, the sliding property is good, and the wear resistance performance. Is improved. Therefore, the measurement accuracy is improved and the service life is extended.
(2) Since the synthetic resin containing carbon nanofibers has good slidability and improved wear resistance, the bearing portion 112 can be formed integrally with the case body 11. Therefore, the number of parts can be reduced and the manufacturing process can be simplified as compared with the case where a bush or the like is separately required as a bearing. As a result, it is possible to improve manufacturing efficiency and reduce costs. At this time, since the friction coefficient is small and the slidability is good, no lubricant or the like is required between the spindle 12 and the bearing portion 112, so that dust or the like is hardly attached. Furthermore, since the wear resistance is excellent, the bearing 112 and the spindle 12 are not worn even if the spindle 12 is repeatedly slid, the service life is long, and the measurement accuracy is maintained for a long time. Can do.
[0029]
(3) Since the synthetic resin containing carbon nanofibers has good mold transferability, the case main body 11, the spindle 12, and the power transmission member 13 can be formed by injection molding. At this time, the case body 11 is formed including the bearing portion 112. The spindle 12 can be formed including a rack 121, and there is no need to perform machining or surface finishing after injection molding. Even when a more advanced surface finishing is performed, the finishing process can be shortened compared to the conventional method. Therefore, the manufacturing process can be simplified and the cost can be reduced.
[0030]
(4) Since each gear of the power transmission unit 13 is formed of a synthetic resin containing carbon nanofibers, the gears (pinion 131, large gear 132, pointer shaft 133, backlash prevention gear 134 are maintained while maintaining rigidity. ) Can be reduced in size and thickness. Therefore, the dial gauge 1 itself can be reduced in size and weight.
(5) Since the case body 11 is formed of a synthetic resin containing carbon nanofibers, the case body 11 can be thinned while maintaining rigidity. Therefore, the dial gauge 1 can be reduced in size and weight.
[0031]
(6) Since the spindle 12 is made of a synthetic resin containing carbon nanofibers, the spindle 12 is reduced in weight while maintaining rigidity. Therefore, even when the spindle 12 contacts the object to be measured, the object to be measured and the spindle 12 are not deformed by the load, and the measurement accuracy is improved. Since the case main body 11 is also formed of a synthetic resin including carbon nanofibers, the case main body 11 is also reduced in weight. As a result, it is possible to reduce the weight of the dial gauge 1 and to improve handling such as carrying.
[0032]
(7) Since the linear expansion coefficient is small, the spindle 12 or the like is not deformed even under severe measurement conditions such as high temperature or low temperature, and precise measurement can be performed.
(8) Since the case body 11 and the spindle 12 are made of a synthetic resin, they are easily adapted to the hand even when they are held by hand, and there is no concern about metal allergies.
[0033]
(Second Embodiment)
FIG. 2 shows a digital dial gauge 2 as a second embodiment of the dial gauge of the present invention. The basic configuration is the same as that of the first embodiment, but the second embodiment is different from the first embodiment in the following points.
The spindle 12 is provided with a capacitance scale 123 along the axial direction. In this scale 123, conductive portions 123A and insulating portions 123B are formed as electrode patterns at a predetermined pitch along the axis of the spindle 12. FIG. 3 shows an enlarged view in which the spindle 12 is partially broken. The insulating part 123B is the spindle 12 itself, that is, the spindle 12 is formed as an insulator with a synthetic resin including carbon nanofibers. The conductive portion 123 </ b> A is obtained by double-molding the spindle 12 on the spindle 12 after the spindle 12 is injection molded and then provided with conductivity by a synthetic resin containing carbon nanofibers.
[0034]
Inside the case main body 11 are provided a detection head 15 that detects the amount of displacement of the spindle 12 by electrostatic coupling with the electrode pattern of the scale 123, and an electric circuit 16 that performs arithmetic processing on the detection value from the detection head 15. ing. The detected value subjected to the calculation process is displayed as a measured value on a display unit (not shown). Here, the case body 11 is made of synthetic resin containing carbon nanofibers and having conductivity.
[0035]
According to such a configuration, in addition to the effects (1), (2), (5), (6), (7), and (8) of the first embodiment, the following effects can be achieved.
(9) Since the case main body 11 has conductivity, the case main body 11 serves as an electromagnetic shield, and the internal electric circuit 16 is shielded from an external magnetic field and electric field. As a result, since the electric circuit 16 inside the case body 11 is protected, damage and malfunction can be prevented, and the measurement accuracy can be kept accurate.
(10) Since the spindle 12 is an insulator, static electricity does not travel from the outside through the spindle 12 and enter the case body 11. For example, even if this spindle 12 is brought into contact with a charged object to be measured, electricity does not travel through the spindle 12 and enter the internal electric circuit 16. Therefore, breakage and malfunction of the electric circuit 16 can be prevented, and the measurement accuracy can be kept accurate.
(11) The electrode pattern of the scale 123 is directly formed on the spindle 12. That is, after the spindle 12 is injection-molded as an insulator with a synthetic resin containing a nanoscale substance, a conductive electrode is further double-molded with a synthetic resin containing a nanoscale substance. Therefore, an electrode pattern can be manufactured simply and at low cost.
(12) Since the electrode pattern is formed around the axis of the spindle 12, the detection head 15 can be electrostatically coupled even if the spindle 12 rotates about the axis. Therefore, there is no need to provide a rotation stop for the spindle 12 or the like. As a result, the manufacturing process can be simplified and the dial gauge 2 can be miniaturized.
[0036]
The dial gauge of the present invention is not limited to the above embodiment. Of course, various modifications can be made without departing from the scope of the present invention.
In the second embodiment, the spindle 12 has an electrode pattern formed on the entire periphery around the axis. For example, as shown in FIG. 4, a part of the spindle 12 is notched in a plane along the axis. Thus, an electrode pattern may be formed on this plane portion. According to such a configuration, the electrostatic coupling between the detection head 15 and the scale 123 can be ensured, for example, the gap holding between the detection head 15 and the scale 123 can be ensured.
[0037]
In the above embodiment, not only the case body 11 but also the spindle 12 and the power transmission unit 13 are formed of synthetic resin including carbon nanofibers. However, the spindle 12 and the power transmission unit 13 include carbon nanofibers. Instead of a synthetic resin, it may be made of metal, for example. If the case body 11 is integrally formed by injection molding with a synthetic resin including carbon nanofibers including the bearing portion 112, the cost can be reduced by reducing the number of parts and simplifying the production line.
In the above embodiment, the bearing portion 112 is formed on the case body 11, but the bearing portion that supports the tip end side (the contact portion 122 side) of the spindle 12 may be provided on the stem 111.
[0038]
In the above embodiment, the case body 11, the spindle 12 and the power transmission unit 13 are not subjected to machining or surface finishing after injection molding with a synthetic resin containing carbon nanofibers. Of course, surface finishing may be performed. A synthetic resin containing carbon nanofibers has a hardness equivalent to that of a steel material, and is therefore easier to machine than conventional synthetic resins.
[0039]
In the second embodiment, the scale 123 of the spindle 12 is formed so as to be accommodated in the case main body 11, but the scale 123 may be exposed to the outside of the case main body 11 when the spindle 12 is slid. This is because if the scale 123 is formed of a synthetic resin containing carbon nanofibers, the scale 123 may be a sliding portion because it is excellent in wear resistance and slidability. According to such a configuration, the length of the spindle 12 can be shortened, and as a result, the dial gauge 2 can be reduced in size.
[0040]
The nanoscale material is not limited to a carbon nanofiber, and a nanoscale material having carbon as a main component such as a carbon nanotube or fullerene can be used.
As the base material of the synthetic resin, polystyrene, polycarbonate, or the like can be used.
[0041]
【The invention's effect】
As described above, according to the dial gauge of the present invention, it is possible to produce an excellent effect that it can be easily manufactured, the measurement accuracy is improved, and the service life can be extended.
[Brief description of the drawings]
FIG. 1 is a view in which a back cover of a pointer type dial gauge is removed as a first embodiment of a dial gauge of the present invention.
FIG. 2 is a diagram showing a digital dial gauge as a second embodiment of the dial gauge of the present invention.
FIG. 3 is a partially cutaway view showing a scale of a spindle in the second embodiment.
FIG. 4 is a view showing a modification of the spindle of the second embodiment.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1, 2 Dial gauge 11 Case main body 12 Spindle 13 Power transmission part 16 Electric circuit 112 Bearing part 121 Rack (power transmission member)
123 Scale 123A Conductive part 123B Insulating part 131 Pinion (power transmission member)
132 Large gear (power transmission member)
133 Pointer shaft (power transmission member)
134 Backlash prevention gear (power transmission member)

Claims (6)

A case main body provided with an electric circuit therein, a spindle, and a bearing portion provided in the case main body for supporting the spindle slidably in the axial direction;
The case body and the bearing portion are integrally formed of a synthetic resin containing a nanoscale material ,
The case body is dial gauge according to claim Rukoto which have a conductivity. The dial gauge according to claim 1,
The case main body and the bearing portion are formed by injection molding. The dial gauge according to claim 1 or 2,
The spindle is formed by injection molding of a synthetic resin containing a nanoscale material. The dial gauge according to any one of claims 1 to 3,
The spindle includes a scale having an electrode pattern in which conductive portions and non-conductive portions are alternately formed along the axial direction;
The scale is formed by injection molding of a synthetic resin containing a nanoscale material. In the dial gauge according to any one of claims 1 to 4,
The case body includes a power transmission member that transmits a displacement movement of the spindle therein,
The power transmission member is formed by injection molding of a synthetic resin containing a nanoscale substance. In the dial gauge according to any one of claims 1 to 5,
A dial gauge characterized in that the nanoscale material is one of carbon nanoscale materials represented by carbon nanofibers or carbon nanotubes.

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