JP6595945B2 - Pirani vacuum gauge - Google Patents

Description

  The present invention relates to a Pirani gauge, and more particularly to a structure having a structure capable of effectively suppressing filament breakage due to vibration or impact.

  This type of Pirani gauge is known from Patent Document 1, for example. This is a cylindrical envelope that can be mounted on an object to be measured such as an airtight container or a vacuum chamber, a linear filament provided in the envelope, and a post-envelope with the mounting direction to the object being measured in front. A terminal block that hermetically holds the side, and a plurality of connection terminals that are electrically insulated from each other and inserted through the terminal block. Further, a filament support longitudinally supported in the front-back direction by one of the connection terminals in the envelope is further provided, and the filament is installed between the front end portion of the filament support and one of the other connection terminals. Generally, the filament support is made of a metal wire having a wire diameter of about φ1 mm.

  Here, in the above-mentioned conventional example, for example, when vibration or impact from a measurement object is applied, the filament and the filament support swing independently of each other starting from the connection terminal to which each is coupled. Become. As a result, unnecessary tensile tension may act on the filament, which causes a problem that the filament is disconnected.

International Publication No. 2006/057148

  In view of the above points, an object of the present invention is to provide a Pirani gauge having a structure capable of effectively suppressing breakage of a filament due to vibration or impact.

  In order to solve the above-described problems, the Pirani vacuum gauge of the present invention has a cylindrical envelope that can be attached to a measurement object, a linear filament provided in the envelope, and a direction in which the measurement object is attached. As a first terminal block that hermetically holds the rear side of the envelope, a plurality of connection terminals that are electrically insulated from and connected to the first terminal block, and one of the connection terminals in the envelope A first filament support longitudinally supported in the front-rear direction, the filament is installed between the front end portion of the first filament support and any other connection terminal, and the first terminal block in the envelope A second terminal block is further provided on the front side, and a first portion in which the connection terminal penetrates the first terminal block, a second portion that penetrates the second terminal block, the first portion, and the first portion Connecting the two parts to each other A second filament support having a holding portion for holding the second terminal block and the front end portion of the first filament support and a connecting portion for connecting the holding portions. It is characterized by becoming.

  According to the present invention, the second terminal block and the first filament support are integrally held by the second filament support. For example, when vibration or impact from the measurement object is applied, the connection terminal Starting from the third portion, the second terminal block held by the second filament support and the first filament support swing together, thereby preventing unnecessary tensile tension from acting on the filament. . Accordingly, the Pirani gauge of the present invention has a structure that can effectively suppress filament breakage due to vibration and impact.

  In the present invention, the second filament support is formed of a cylindrical body that integrally includes the holding portion and the connecting portion and stores the second terminal block and the first filament support. It is preferable. According to this, the structure which hold | maintains a 2nd terminal block and a 1st filament support integrally may be implement | achieved easily. Further, a configuration in which the first filament support and the second filament support are integrally formed may be employed.

Sectional drawing explaining the structure of the Pirani vacuum gauge of embodiment of this invention. FIG. 2 is a partially omitted cross-sectional view showing a state in which vibration is generated in the Pirani vacuum gauge shown in FIG. 1.

  Hereinafter, a Pirani gauge according to an embodiment of the present invention will be described with reference to the drawings. In the following, terminology indicating the direction will be used, with the mounting direction of the measurement object outside the figure as “front (upward in FIG. 1)” and the removal direction as “rear (downward in FIG. 1)”.

With reference to FIG. 1, PG is the Pirani vacuum gauge of this embodiment. The Pirani gauge PG includes a cylindrical envelope 1 having a mounting flange 11 at the front end. The rear end of the envelope 1 is airtightly closed by the first terminal block 2. The first terminal block 2 is provided with a plurality of (two in FIG. 1) connection terminals 3 ₁ , 3 ₂ that are electrically insulated from each other and kept airtight. . The first terminal block 2 can be constituted by a so-called hermetic seal.

A second terminal block 4 is provided in front of the first terminal block 2 in the envelope 1. The second terminal block 4, the second part 3b of the connecting terminals 3 _1, 3 ₂ are fitted through with electrically to insulate from each other. In this case, the second terminal block 4 extends in the radial direction (a direction orthogonal to the front-rear direction), and the third portions 3c of the connection terminals 3 ₁ and 3 ₂ that connect the first portion 3a and the second portion 3b to each other. It is supported by. The second terminal block 4 can also be constituted by a so-called hermetic seal. Each of the portions 3a, 3b, 3c of the connection terminals 3 ₁ , 3 ₂ can be formed by connecting a plurality of metal pin-shaped members to each other by soldering, welding, or the like, or a single metal The pin-shaped member can be formed integrally with the Z-shape.

In the envelope 1, a first filament support 5 that is long in the front-rear direction (vertical direction in FIG. 1) is provided so as to be supported by the second portion 3b of _one connection terminal 31. The first filament support 5 is composed of a metal rod-like or plate-like member whose front end is bent toward the inside of the envelope 1. In this case, for example, the lower end portion of the first filament support 5 fitted through the second terminal block 4, the second portion 3b and the third portion 3c of the connection terminals 3 ₁ integrally with the first filament support 5 You may make it form. A first filament support 5 the front end of the bent portion 51, between the second portion 3b of the other connection terminal 3 _2, linear filament 6 is bridged. As the filament 6, a metal wire having a wire diameter of about φ25 μm is used. And the 2nd filament which has the connection part 73 which connects the holding parts 71 and 72 which hold | maintain the 2nd terminal block 4 and the bending part 51 of the 1st filament support 5, respectively, and both holding parts 71 and 72, respectively. Support 7 is provided.

In the present embodiment, the second filament support 7 is a metal cylinder that integrally includes the holding portions 71 and 72 and the connecting portion 73 and stores the second terminal block 4 and the first filament support 5. It consists of In this case, the lower end of the second filament support 7 as a cylindrical body is opened, and is fitted to the second terminal block 4 through this opening. On the other hand, the upper end of the second filament support 7 is closed, and a bent portion 51 is joined to the upper end surface. Further, an opening 74 facing the filament 6 is formed on the side wall of the second filament support 7. Although not particularly shown and described, the second filament support 7, the second portion from the second portion 3b of the connector 3 ₂ filament 6, the other connection terminals 3 ₁ through the first filament support 5 An insulator is provided as appropriate so as not to short-circuit the current flowing through 3b.

According to the above embodiment, the second terminal block 4 and the first filament support 5 are integrally held by the second filament support 7. For example, when vibration or impact from a measurement object is applied. 2, the second terminal block 4 held by the second filament support 7 and the first filament support 5 are integrated from the third portion 3b of the connection terminals 3 ₁ and 3 ₂ as a starting point. Therefore, unnecessary tension tension is prevented from acting on the filament 6. Therefore, the Pirani vacuum gauge PG of the present embodiment can have a structure that can effectively suppress breakage of the filament 6 due to vibration or impact.

As mentioned above, although embodiment of this invention was described, this invention is not limited to said thing. In the above-described embodiment, the second filament support 7 is formed as a cylindrical body. However, the second terminal block 4 and the first filament support 5 are integrally held by the second filament support 7. If it is done, it will not be limited to the above, The holding parts 71 and 72 and the connection part 73 can also be comprised by another component. In the above-described embodiment, the first portion 3a and the second portion 3b of the connection terminals 3 ₁ and 3 ₂ have been described as being connected by the third portion 3c arranged so as to be orthogonal thereto. If the second terminal block 4 held by the second filament support 7 and the first filament support 5 swing integrally with the third portion 3b as a starting point when vibration is generated, the form is It doesn't matter.

  Furthermore, in the said embodiment, the 1st filament support 5 and the 2nd filament support 7 are made into a different body, and the 1st filament support 5 is hold | maintained integrally with the 2nd terminal block 4 with the 2nd filament support 7. However, the present invention is not limited to this, and the first filament support 5 and the second filament support 7 can be integrally formed by a known method when manufacturing the filament support. .

PG ... Pirani vacuum gauge, 1 ... envelope, 2 ... first terminal block, 3 ₁ , 3 ₂ ... connection terminal, 3a ... first part (connection terminal), 3b ... second part (connection terminal), 3c ... first 3 parts (connection terminals), 4 ... second terminal block, 5 ... first filament support, 6 ... filament, 7 ... second filament support.

Claims (3)

A cylindrical envelope that can be attached to the measurement object, a linear filament provided in the envelope, and a first terminal block that airtightly holds the rear side of the envelope with respect to the direction of attachment to the measurement object. A plurality of connection terminals that are electrically insulated from each other and penetrate the first terminal block, and a first filament support that is longitudinally supported in the envelope by any of the connection terminals. In the Pirani vacuum gauge, the filament is installed between the front end portion of the first filament support and any other connection terminal.
A second terminal block is further provided in the envelope in front of the first terminal block, and the connection terminal is inserted into the first terminal block and the second terminal block. A holding part that holds the second terminal block and the front end part of the first filament support, and holds both of the second part, the first part, and the third part that are connected to each other. A Pirani vacuum gauge, comprising a second filament support having a connecting portion for connecting the portions. The second filament support includes a cylindrical body that integrally includes the holding portion and the connecting portion and stores the second terminal block and the first filament support. Item 4. The Pirani gauge according to Item 1. The Pirani vacuum gauge according to claim 1, wherein the first filament support and the second filament support are integrally formed.

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