JP2005099044A - Movement for measuring instrument - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To securely hold, in cylindrical support hole portions, a support shaft for turnably supporting the rotor of an electric motor built in a resin casing of the movement for a measuring instrument, and a support shaft for turnably supporting an intermediate gear of a reduction gear train, for transmitting the rotation of the electric motor to a pointer shaft after reduction. <P>SOLUTION: On a casing member 10a, the support hole portions 12b and 12c are formed through an upper wall 12 so as to support base portions 41 and 72 of the support shafts 40a and 70c respectively, and the support hole portions 12b and 12c are each provided with an inside diameter of a drawn end side axial hollow portion J2 larger than that of the other axial hollow portion J2, J4, excluding the portion. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a turning inner unit for an instrument.

  2. Description of the Related Art Conventionally, for example, in a rotating internal unit of a passenger car instrument, the internal unit body is configured by assembling a step motor and a reduction gear train driven by the step motor in a resin casing. The reduction gear train includes an output stage gear supported in the casing at an intermediate portion of the pointer shaft extending through the upper wall of the casing, an input stage gear driven by a step motor, an output stage gear, and an input stage. And an intermediate gear meshing with the gear. Here, the rotor and the intermediate gear of the step motor are rotatably supported by pin-shaped metal support shafts each having a circular cross section supported between the upper and lower walls of the casing.

  By the way, in the above rotating inner machine, each metal support shaft is supported on the upper and lower walls by the support shafts in the respective cylindrical support hole portions formed on the lower wall of the casing at the base end portions thereof. It is made by supporting it so that it cannot be rotated by press fitting.

  Since the bottom of each support hole is closed, even if each support shaft is press-fitted into each support hole, there is no air hole in each support hole. Direction in which the bottom of the support hole cannot be completely press-fitted, or the air compressed by the base end of each support shaft in each support hole expands due to temperature and pushes each base end out of each support hole Or the like, causing a problem that each support shaft cannot be securely held in each support hole.

  Therefore, in order to deal with the above-described problems, the present invention provides a support shaft that rotatably supports the rotor of the electric motor assembled in the resin casing in the rotating inner unit for the instrument and the rotation of the electric motor. It is an object of the present invention to firmly hold a support shaft that rotatably supports an intermediate gear of a reduction gear train that decelerates and transmits it to a pointer shaft in each support hole.

  In solving the above-described problem, the turning internal unit for an instrument according to the invention described in claim 1 includes a casing (10) configured by assembling both casing members (10a, 10b) with each other, and each facing wall of both casing members. A pointer shaft (20) rotatably supported by (11, 12), and at least first and second support shafts (40a, 70c) made of metal supported between the opposing walls of both casing members. An electric motor (M) having a rotor (70) mounted in a casing and rotatably supported by a first support shaft, an input stage gear (60) driven by the electric motor, and a relative rotation with respect to a pointer shaft An output stage gear (30) that is impossiblely supported and an intermediate gear (40, 50) that is rotatably supported by the second support shaft so as to mesh between the input stage gear and the output stage gear; Deceleration teeth housed in the casing And a column (G).

  In the rotating inner unit, one of the opposing walls of the two casing members (12) has a corresponding portion with respect to the base end portions (41, 72) of the first and second support shafts. Support hole portions (12b, 12c, 12d, 12e, 12f, 12f, 12f, 12f, 12f, 12b, 12e, 12f) that extend in a cylindrical shape from the inner surface of one of the opposing walls along the axial direction of the first and second support shafts. 12g) are formed in parallel with each other, and for each of the first and second support hole portions, the inner diameter of the extension end side axial hollow portion (J2) of the support hole portion is the support hole Each of the first and second support shafts has a base end portion that is larger than the inner diameter of the remaining axial hollow portion (J3, J4) excluding the extended-end-side axial hollow portion. The remaining axial hollow portions are inserted into the corresponding support hole portions through the extending end side axial hollow portions. Is coaxially pressed into, and wherein the extending toward the other of the opposed walls (11).

  In this way, when the first and second support shafts are press-fitted, the base end portions thereof are press-fitted into the corresponding remaining axial hollow portions through the corresponding extended end-side axial hollow portions. However, each extension end side axial hollow portion has an inner diameter larger than the corresponding inner diameter of each remaining axial hollow portion, and thus the outer diameter of the base end portion of each support shaft. Thereby, the crack of each support hole part can be prevented beforehand by each said remaining axial direction hollow part. This means that the extended end side axial hollow portion of each support hole has a role of preventing cracking when the support shaft is press-fitted.

  In addition, the code | symbol in the bracket | parenthesis of each said means shows the correspondence with the specific means as described in embodiment mentioned later.

  Hereinafter, each embodiment of the present invention will be described with reference to the drawings.

(First embodiment)
FIG. 1 shows an example in which the present invention is applied to a passenger car instrument, and this instrument is disposed on an instrument panel (not shown) provided in the passenger compartment of the passenger car. As shown in FIG. 1, the instrument includes a wiring board P and a rotating inner unit D. The rotating inner unit D includes a resin casing 10 attached to the back surface of the wiring board P, a metal pointer shaft 20, and a step motor M and a reduction gear train G assembled in the casing 10. Here, the casing 10 is configured by fitting both casing members 10a and 10b having a U-shaped cross section into each other at their openings.

  The pointer shaft 20 is supported at the base end portion 21 in a cylindrical support hole portion 11a formed in the lower side wall 11 in the casing 10 so as to be rotatable. A cylindrical portion 12a formed on the upper wall 12 passes through the base end portion 21 coaxially and rotatably. As a result, the pointer shaft 20 is supported coaxially and rotatably by the casing 10 with the support hole portion 11a and the cylindrical portion 12a.

  The reduction gear train G includes an output stage gear 30, both intermediate gears 40 and 50, and an input stage gear 60. The output stage gear 30 is configured by integrally forming a cylindrical support hole 30b on a large-diameter spur gear part 30a. The output stage gear 30 is fitted with the pointer shaft 20 in the support hole 30b. It is coaxially supported by the coaxial part 20a. In FIG. 1, reference numeral 13 denotes a curved spring that biases the output stage gear 30.

  The intermediate gear 50 is rotatably supported by a cylindrical boss on a metal pin-shaped support shaft 40 a having a circular cross section, and the intermediate gear 40 is coaxially rotated relative to the boss of the intermediate gear 50. It is supported immovably. Here, the intermediate gear 40 is a pinion gear, and the intermediate gear 50 is a spur gear. The intermediate gear 40 is a gear having a smaller diameter than the spur gear portion 30a and the intermediate gear 50, and meshes with the spur gear portion 30a. The support shaft 40a is supported between the upper and lower walls 12 and 11 so as not to rotate on the right side of the pointer shaft 20 in FIG.

  The input stage gear 60 is coaxially supported by a cylindrical support hole 71 of a magnet rotor 70 (described later) of the step motor M. The input stage gear 60 includes a pinion gear having a smaller diameter than the spur gear portion 30 a and the intermediate gear 50, and meshes with the intermediate gear 50. In the present embodiment, the output stage gear 30, the both intermediate gears 40 and 50, and the input stage gear 60 are formed of a synthetic resin (for example, a soft synthetic resin) that does not generate or at least hardly generates a meshing sound.

  The step motor M includes a magnet rotor 70 and an annular yoke 80. The magnet rotor 70 is formed by fitting a cylindrical rotor portion 70a made of a non-magnetic material and a large number of magnet portions 70b along the circumferential direction on the outer peripheral surface of the rotor portion 70a. The cylindrical support hole 71 is rotatably supported coaxially on a metal pin-shaped support shaft 70c having a circular cross section. The large number of magnet parts 70b are formed by alternately fitting N magnetic pole parts and S magnetic pole parts to the outer peripheral surface of the rotor part 70a. Further, the support shaft 70c is supported between the upper and lower walls 12 and 11 in a non-rotatable manner on the right side of the support shaft 40a in FIG.

  The yoke 80 is interposed between the openings of the casing members 10a and 10b of the casing 10, and the yoke 80 constitutes a stator of the step motor M together with each field winding (not shown).

  Next, the support structure with respect to the casing 10 of both the support shafts 40a and 70c is demonstrated in detail. The casing member 10a includes both cylindrical support holes 12b and 12c. The support hole portion 12b is formed in a portion that should support the base end portion 41 of the support shaft 40a in the upper wall 12 and is formed so as to protrude from the portion toward the lower wall 11 in a cylindrical shape. Yes.

  Accordingly, the support shaft 40a is press-fitted coaxially and non-rotatably into the support hole portion 12b of the upper wall 12 at the base end portion 41, and the tip end portion 42 of the support shaft 40a is The lower wall 11 is supported coaxially in the support hole 11b. Here, the inner diameter of the cylindrical portion 12b is somewhat smaller than the outer diameter of the base end portion 41 of the support shaft 40a. The support hole portion 11b is positioned coaxially with the cylindrical portion 12b.

  On the other hand, the support hole 12c is formed in a penetrating manner in a portion of the upper wall 12 that should support the base end portion 72 of the support shaft 70c, and the support hole 12c is supported on the inner surface of the upper wall 12. The shaft 70 c protrudes in a cylindrical shape from the portion that should support the base end portion 72 toward the lower wall 11.

  Accordingly, the support shaft 70c is press-fitted coaxially and non-rotatably into the support hole portion 12c of the upper wall 12 at the base end portion 72, and the distal end portion 73 of the support shaft 70c is The lower wall 11 is supported coaxially in the support hole 11c. Here, the inner diameter of the cylindrical portion 12c is somewhat smaller than the outer diameter of the base end portion 72 of the support shaft 70c. In addition, the support hole part 11c is coaxially located with the cylinder part 12c, and each axis | shaft of both cylinder parts 12b and 12c is mutually parallel.

  In the first embodiment, both casing members 10a and 10b are injection-molded with resin by an injection mold. Here, as described above, since each cylindrical support hole 12b, 12c of the casing member 10a is formed in a penetrating manner in the upper wall 12, each support hole 12b, 12c is formed in the upper wall 12. It opens from the outer surface to the outside. Correspondingly, the injection mold has pin-like portions corresponding to the through-holes of the support hole portions 12b and 12c in parallel with each other.

  Therefore, during the injection molding of the casing member 10a, the air in the through-holes of the support hole portions 12b and 12c is not completely left in the resin but is completely pushed out by the pin-shaped portions. Therefore, each support hole part 12b, 12c can be shape | molded so that it may mutually protrude from the inner surface of the upper wall 12. As shown in FIG.

  In the first embodiment configured as described above, the support hole portions 12b and 12c both extend in parallel from the inner surface of the upper wall 12 as described above. Accordingly, when the base end portions 41 and 72 of the both support shafts 40a and 70c are press-fitted into the corresponding support hole portions 12b and 12c as shown by the respective arrows shown in FIG. Can be maintained parallel to each other by the top wall 12.

  Here, since each support hole 12b, 12c is opened outward from the outer surface of the upper wall 12, when each base end 41, 72 is press-fitted into the corresponding support hole 12b, 12c, The air in the hollow portions of the support hole portions 12 b and 12 c is pushed outward by the base end portions 41 and 72. Accordingly, the base end portions 41 and 72 can be sufficiently press-fitted into the corresponding support hole portions 12b and 12c, as well as the support hole portions even if the air in the support hole portions 12b and 12c expands. It flows out of the outer surface side of the upper wall 12 from 12b, 12c. Therefore, the press-fitted state of the base end portions 41 and 72 into the support hole portions 12b and 12c is maintained well without causing the base end portions 41 and 72 to slip out of the support hole portions 12b and 12c. Can be done.

  As a result, when the magnet rotor 70a is rotatably supported by the support shaft 70c, and the intermediate gear 50 is rotatably supported by the support shaft 40a, the magnet rotor 70a is coaxially formed by the support hole 71 of the magnet rotor 70a. The input stage gear 60 supported so as not to rotate can mesh well with the intermediate gear 50.

(Second Embodiment)
FIG. 3 shows a second embodiment of the present invention. In the second embodiment, the upper wall 12 of the casing member 10a described in the first embodiment has both cylindrical support holes 12d and 12e instead of the both cylindrical support holes 12b and 12c. Both the support hole portions 12d and 12e are formed in the upper wall 12 so as to penetrate in the same manner as the both support hole portions 12b and 12c. However, the support hole portions 12d and 12e are respectively formed in the support hole portions 12b. , 12c, each has a stepped cylindrical hollow portion H.

  The stepped cylindrical hollow portion H includes a large diameter portion H1 and a small diameter portion H2 that is coaxially connected to the large diameter portion H1 on the outer surface side of the upper wall 12. The opening h on the inner surface side of the upper wall 12 of the large-diameter portion H1 is formed in a tapered cross section so that one of the support shafts 40a and 70c can be easily inserted into the large-diameter portion H1. Further, the inner diameter of the small-diameter portion H2 is a value that can easily push the air in the stepped cylindrical hollow portion H to the outer surface side of the upper wall 12. Here, the axial length of the large diameter portion H1 corresponds to the axial length of the base end portion 41 of the support shaft 40a and the base end portion 72 of the support shaft 70c (corresponding to the press-fit length of the support shafts 40a and 70c). Is almost equal to

  Here, the casing member 10a is injection-molded with an injection mold with resin as in the first embodiment, but as described above, each support hole 12d, 12e is a hollow hollow with a stepped step. Since it has the portion H, in accordance with this, the injection mold is parallel to the stepped pin-shaped portions corresponding to the through-shaped stepped cylindrical hollow portions H of the support hole portions 12d and 12e, respectively. Have.

  Therefore, during the injection molding of the casing member 10a, the air in the through-hole stepped cylindrical hollow portion H of each of the support hole portions 12d and 12e does not remain in the resin, and the stepped pin-shaped portion causes the air from the small diameter portion H2. Extruded completely. Accordingly, the support hole portions 12d and 12e can be formed so as to protrude from the inner surface of the upper wall 12 in parallel with each other. Other configurations are the same as those in the first embodiment.

  In the second embodiment configured as described above, the support hole portions 12d and 12e extend in parallel from the inner surface of the upper wall 12 as described above. Therefore, when both the support shafts 40a and 70c are press-fitted into the corresponding support hole portions 12d and 12e at the respective base end portions 41 and 72, the both support shafts 40a and 70c are maintained parallel to each other by the upper wall 12. obtain.

  Here, since the opening h of the stepped cylindrical hollow portion H of each of the support holes 12d and 12e is formed in a tapered shape in cross section, each support of the base end portions 41 and 72 of the both support shafts 40a and 70c is supported. The press-fitting into the holes 12d and 12e can be easily and reliably performed. Further, since the support hole portions 12d and 12e are opened outward from the outer surface of the upper wall 12 at the small diameter portions H2, the base end portions 41 and 72 are connected to the corresponding support hole portions 12d. , 12e, the air in the stepped cylindrical hollow portion H of the support hole portions 12d, 12e is pushed outward from the small diameter portions H2 by the base end portions 41, 72.

  Accordingly, the base end portions 41 and 72 can be sufficiently press-fitted into the large-diameter portions H1 of the corresponding support hole portions 12d and 12e, and air in the support hole portions 12d and 12e expands. However, it flows out of the outer surface side outward of the upper wall 12 from each small diameter part H2. Therefore, the press-fitted state of the base end portions 41 and 72 into the support hole portions 12d and 12e can be satisfactorily maintained without causing the base end portions 41 and 72 to slip out from the large-diameter portion H1. As a result, the effect can be achieved as in the first embodiment.

(Third embodiment)
FIG. 4 shows a third embodiment of the present invention. In the third embodiment, the upper wall 12 of the casing member 10a described in the first embodiment has both cylindrical support holes 12f and 12g instead of the both cylindrical support holes 12b and 12c. Both the support hole portions 12f and 12g are formed in the upper wall 12 so as to penetrate in the same manner as the support hole portions 12b and 12c. The support hole portions 12f and 12g are formed in the support hole portions 12b. , 12c, each has a stepped cylindrical hollow portion J.

  The stepped cylindrical hollow portion J includes a tapered opening J1, a large diameter portion J2, and a small diameter portion J3 coaxially communicating with the opening portion J1 via the large diameter portion J2. The attached cylindrical hollow portion J opens to the inner surface side of the upper wall 12 at the opening portion J1, and opens to the outer surface side of the upper wall 12 at the small diameter portion J3. Further, the inner diameter of the small diameter portion J3 is equal to the inner diameter of the support hole portion 12c described in the first embodiment.

  In addition, the large-diameter portion J2 having an inner diameter larger than the small-diameter portion J3 is provided between the opening J1 and the small-diameter portion J3 because the corresponding support hole portions 12g and 12f of the respective support shafts 40a and 70c are provided. With the press-fitting position and press-fitting length properly secured, the cracks in the support hole portions 12g and 12f are not generated when the support shafts 40a and 70c corresponding to the support hole portions 12g and 12f are press-fitted. This is to prevent it. For this reason, the press-fit length of one of the proximal end portions of the support shafts 40a and 70c in the small diameter portion J3 of the stepped cylindrical hollow portion J is B, and the sum of the axial lengths of the opening J1 and the large diameter portion J2 is A. Is set so that (A / B) = (1/2).

  Here, the casing member 10a is injection-molded with an injection mold with resin as in the first embodiment. However, as described above, each of the support holes 12f and 12g has a cylindrical hollow with a stepped shape. Since it has the portion J, the injection molding die is parallel to the stepped pin-shaped portions corresponding to the through-shaped stepped cylindrical hollow portions J of the support hole portions 12f and 12g. Have. Therefore, during the injection molding of the casing member 10a, the air in the through-hole stepped cylindrical hollow portion J of each of the support hole portions 12f and 12g does not remain in the resin, and the stepped pin-shaped portion causes the air from the small diameter portion J3. Extruded completely. Therefore, each support hole part 12f, 12g can be shape | molded so that it may mutually protrude from the inner surface of the upper wall 12. FIG. Other configurations are the same as those in the first embodiment.

  In the third embodiment configured as described above, the support hole portions 12f and 12g both extend in parallel from the inner surface of the upper wall 12 as described above. Therefore, when the two support shafts 40a and 70c are press-fitted into the corresponding support hole portions 12f and 12g at the base end portions 41 and 72, the support shafts 40a and 70c are maintained parallel to each other by the upper wall 12. obtain.

  Here, since the opening J1 of the stepped cylindrical hollow portion J of each support hole 12f, 12g is formed in a tapered shape in cross section, each support of each base end portion 41, 72 of both support shafts 40a, 70c. The press-fitting into the holes 12f and 12g can be easily and reliably performed. Further, when the support shafts 40a and 70c are press-fitted, the base end portions 41 and 72 are made to correspond to the small diameter portions J3 through the corresponding large diameter portions J2, but the large diameter portions J2 The supporting shaft 40a has an inner diameter larger than the outer diameter of the base end portion of each of the support shafts 40a and 70c, and the sum A of the axial lengths of the opening J1 and the large diameter portion J2, respectively. The ratio (A / B) of one press-fit length B at the base end portion of 70c is substantially (1/2). Thereby, the cracks of the support hole portions 12f and 12g are prevented in advance by the corresponding large diameter portions J2, and the press fitting of the support shafts 40a and 70c into the corresponding support hole portions 12f and 12g is properly performed. Can be made.

  Further, since the support hole portions 12f and 12g are opened outward from the outer surface of the upper wall 12 at the respective small diameter portions J3, the base end portions 41 and 72 are respectively connected to the corresponding support hole portions 12f. , 12g, the air in the stepped cylindrical hollow portion J of each of the support hole portions 12f, 12g is pushed outward from the respective small diameter portions J3 by the respective base end portions 41, 72. Accordingly, the base end portions 41 and 72 can be sufficiently press-fitted into the corresponding small diameter portions J3 of the support hole portions 12f and 12g, and the air in the support hole portions 12f and 12g expands. Also flows out of the outer surface side of the upper wall 12 from each of the small diameter portions J3. Therefore, the press-fitted state of the base end portions 41 and 72 into the support hole portions 12f and 12g can be satisfactorily maintained without causing the base end portions 41 and 72 to slip out from the small diameter portion J2. Other functions and effects are the same as those of the first embodiment.

(Fourth embodiment)
5 and 6 show a fourth embodiment of the present invention. In the fourth embodiment, in each cylindrical support hole 12f, 12g of the upper wall 12 of the casing member 10a described in the third embodiment, the cross-section cylindrical stepped hollow portion J is formed on the small diameter portion J3. Instead, it has a cylindrical rib portion J4. The rib portion J4 has a plurality of ribs a, and each of the ribs a has a cross section extending from the inner peripheral surface of the hollow portion having the same diameter as that of the large diameter portion J2 toward the axis of the rib portion J4. It is formed so as to protrude in an equal triangular shape. Here, each rib a is located along the circumferential direction of the rib part J4 at predetermined intervals, and each of these ribs a is located along the axial direction of the rib part J4. In addition, the top part of each rib a of the rib part J4 is located on the inner peripheral surface of the small diameter part J3. Other configurations are the same as those of the third embodiment.

  In the fourth embodiment configured as described above, both the support shafts 40a and 70c are press-fitted into the corresponding support hole portions 12f and 12g at the base end portions 41 and 72, as in the third embodiment. In this case, the support shafts 40 a and 70 c can be maintained parallel to each other by the upper wall 12.

  Here, when the both support shafts 40a and 70c are press-fitted, the base end portions 41 and 72 are made to the corresponding rib portions J4 through the corresponding large diameter portions J2, and the top portions of the ribs a are Thus, since it is located on the inner peripheral surface of the small diameter portion J3 described in the third embodiment, the base end portions 41 and 72 are press-fitted by crushing the ribs a in the corresponding rib portions J4. The Therefore, press-fitting into the corresponding rib portions J4 of the support shafts 40a and 70c can be appropriately performed. Other functions and effects are the same as those of the third embodiment.

(Fifth embodiment)
7 and 8 show a fifth embodiment of the present invention. In the fifth embodiment, in the upper wall 12 of the casing member 10a described in the third embodiment (see FIG. 4), the support hole portion 12b has a plurality of ribs b, and the support hole portion 12c has a plurality of support holes 12c. Ribs c are provided. As shown in FIGS. 7 and 8, each rib b extends outward in a triangular wall shape from the outer peripheral surface of the support hole portion 12b to the inner surface of the upper wall 12, and each rib c has an outer periphery of the support hole portion 12c. A triangular wall shape extends outwardly from the surface into the inner recess of the wall 12. Each of the support holes 12b and 12c is formed in a tapered cross section at the inner surface side opening d of the upper wall 12 thereof. Other configurations are the same as those in the first embodiment.

  In the fifth embodiment configured as described above, both the support shafts 40a and 70c are press-fitted into the corresponding support hole portions 12b and 12c at the respective base end portions 41 and 72 as in the first embodiment. Sometimes, both support shafts 40a, 70c can be maintained parallel to each other by the top wall 12.

  Here, as described above, the plurality of ribs b are formed in a triangular wall shape on the outer peripheral surface of the support hole portion 12b, and the plurality of ribs c are formed in a triangular wall shape on the outer peripheral surface of the support hole portion 12c. Therefore, when the support shaft 40a is press-fitted into the support hole 12b, the support hole 12b is prevented from being deformed in the radial direction and outward by the ribs b. Thereby, the crack of the said support hole 12b at the time of the support shaft 40a to the support hole 12b can be prevented.

  Further, when the support shaft 70c is press-fitted into the support hole 12c, the support hole 12c is prevented from being deformed in the radial direction and outward by the ribs c. Thereby, while preventing the crack of the support hole portion 12c when the support shaft 70c is inserted into the support hole portion 12c, the support shafts 40a and 70c are properly pressed into the corresponding support hole portions 12b and 12c. Can be maintained. Each opening d facilitates press-fitting of the support shafts 40a and 70c into the support holes 12b and 12c. Other configurations are the same as those in the first embodiment.

  In implementing the present invention, unlike the first embodiment, the support holes corresponding to the support holes 12b and 12c of the upper wall 12 are formed in the lower wall 11 in a penetrating manner. Even if it is configured to press-fit the tip portions of the support shafts 40a and 70c into the portions, substantially the same operational effects as in the above embodiment can be achieved. This is substantially the same in other embodiments.

  Further, in carrying out the present invention, instead of the respective cylindrical support holes 12b, 12c formed in the upper wall 12 of the casing 10a described in the first embodiment, the respective through-hole portions formed in the upper wall 12 The base end portions of the support shafts 40a and 70c may be press-fitted into the through-hole portions.

  In implementing the present invention, various electric motors may be used in place of the step motor M.

  Moreover, in carrying out the present invention, the present invention may be generally applied to automobiles and other vehicles, marine instruments, and other various instruments without being limited to passenger car instruments.

It is principal part sectional drawing which shows 1st Embodiment of this invention. It is sectional drawing which shows the state which press-fitted the casing member to both the support hole parts of the upper wall with both the support shafts of FIG. It is a fragmentary sectional view showing an important section of a 2nd embodiment of the present invention. It is a fragmentary sectional view showing an important section of a 3rd embodiment of the present invention. It is sectional drawing which follows the 5-5 line in FIG. It is a fragmentary top view which shows the principal part of 4th Embodiment of this invention. It is sectional drawing which follows a 7-7 line | wire in FIG. It is a fragmentary top view which shows the principal part of 5th Embodiment of this invention.

Explanation of symbols

10 ... casing, 10a, 10b ... casing member, 11 ... lower wall,
12 ... Upper wall, 12b, 12c, 12d, 12e, 12f, 12g ... Support hole, 20 ... Pointer shaft, 30 ... Output gear, 40a, 70c ... Support shaft,
41, 72 ... proximal end, 60 ... input gear, 70 ... magnet rotor,
G: Reduction gear train, J2: Large diameter portion, J3: Small diameter portion, J4: Rib portion,
M: Step motor.

Claims (1)

A casing (10) configured by assembling both casing members (10a, 10b);
A pointer shaft (20) rotatably supported by the opposing walls (11, 12) of both casing members;
At least first and second support shafts (40a, 70c) made of metal supported between the opposing walls of the two casing members;
An electric motor (M) having a rotor (70) mounted in the casing and rotatably supported by the first support shaft;
The input stage gear (60) driven by the electric motor, the output stage gear (30) supported so as not to rotate relative to the pointer shaft, and the input stage gear and the output stage gear so as to mesh with each other. In the turning internal unit for an instrument having an intermediate gear (40, 50) rotatably supported on the second support shaft, and comprising a reduction gear train (G) accommodated in the casing,
One of the opposing walls of the two casing members (12) is connected to each base end (41, 72) of the first and second support shafts from the inner surface of the one opposing wall. Support holes (12b, 12c, 12d, 12e, 12f, 12g) extending in a cylindrical shape toward the other opposing wall along the axial direction of the first and second support shafts are formed in parallel to each other. Has been
For each of the first and second support holes, the inner diameter of the extension end side axial hollow portion (J2) of the support hole portion is the extension end side axial hollow of the support hole portion. It is larger than the inner diameter of the remaining axial hollow portion (J3, J4) excluding the portion,
The respective base end portions of the first and second support shafts are inserted into the corresponding support hole portions through the extending-end-side axial hollow portions and are coaxially press-fitted into the remaining axial hollow portions. And a rotating inner unit for an instrument characterized by extending toward the other opposing wall (11).

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