JPH0566009B2 - - Google Patents

Description

[Detailed Description of the Invention] (Industrial Application Field) The present invention relates to multilayer ceramic chip capacitors, etc.
Regarding measurement units used to measure characteristics such as electric capacitance of chip-shaped electronic components, it is particularly suitable for holding chip-shaped electronic components on an index table and automatically measuring various electrical characteristics during intermittent rotational movement. This invention relates to a unit for measuring characteristics.

(Prior Art) Conventionally, capacitance measurement methods for this type of chip capacitor include a so-called one-side contact method and a so-called opposite contact method. FIG. 7 shows the case of the one-side contact method, in which round or square rods or square rods are attached from above to the upper surfaces or upper corners of the external electrodes 2, 2' at both ends of the chip capacitor 1 placed horizontally on the mounting table 5. Capacitance is measured by bringing the flat end surface of a rod-shaped measurement electrode terminal (contactor) 3 into contact. In contrast, Fig. 8 a, b
is an example of the facing contact method, in which the measuring contacts 3 are arranged so that their end faces face each other, and both ends of the chip capacitor 1 are sandwiched between them to measure the capacitance. In the facing contact method, the contactors 3 on both sides are movable as shown in Fig. 8a, and one contactor 3' is fixed as shown in Fig. 8b, and the end surface of the fixed contactor 3' is The chip capacitor 1 is applied to and positioned, and the other movable side contact 3 is guided by a linear guide 4 and moved in a reciprocating straight line, or the movable side contact 3 is formed into an arm shape as shown in Fig. 8c. The base portion 3a of the lever is pivotally supported by a fulcrum pin 6, and the structure is such that the base portion 3a is oscillated around the fulcrum pin 6. If the contacts on both sides are movable, the 8th
As shown in Figure a, only linear movement is performed by the linear guide 4, and no swinging method is used.

(Problem to be solved by the invention) Characteristic measurement of chip parts using the opposing contact method is
As mentioned above, since a pair of contacts are opposed and the chip part is fed between them, there is less variation in measurement than the one-sided contact method, and it is suitable for highly accurate and minute capacitance measurements, but unlike the conventional facing contact method, A structure in which the measurement contact is restrained by a linear guide and moved in a straight line has a disadvantage that the sliding resistance is greater than that of a swing mechanism, and the structure is large and complicated, making it difficult to operate at high speed. When a swinging structure using a fulcrum pin 6 as shown in Fig. 9 is adopted in a facing contact system with both sides movable, the distance L between the fulcrums cannot be made close due to the large diameter of the shaft support at the base of the contact. The tip of the capacitor 3 swings diagonally toward and away from the electrode surface of the chip capacitor 1, which improves measurement accuracy and
This method cannot be adopted due to measurement dispersion. Even when the contact is fixed on one side and the movable side is oscillating as shown in FIG. The distance between the contact element 3' and the fixed side contact element 3' becomes large, and the contact element 3' does not contact the end face of the chip capacitor perpendicularly, which is an obstacle to improving measurement accuracy. In addition, with shaft rotation support, it is difficult to control the swing stroke within a minute range, and there is a drawback that nimble and precise movements cannot be performed.

(Means for Solving the Problems) A characteristic measuring unit for chip parts according to the present invention is an open/close unit arranged above an index table that holds chip parts and pivoted to move up and down with respect to the index table. a member driving cam plate, a vertical drive mechanism for the driving cam plate, an opening/closing member support plate disposed between the driving cam plate and the index table and fixed to the apparatus main body, and the opening/closing member supporting plate. a pair of opening/closing members which penetrate through a member support plate, have a midway portion supported by the support plate in a knife-edge manner, and are provided with a measuring contact at a lower end; A pair of spring means biasing the opening/closing member in a direction in which its lower end closes, and a cam plate provided at the tip of the opening/closing member driving cam plate and tapered into engagement with the upper end of the opening/closing member. , the vertical drive mechanism for the opening/closing member driving cam plate is configured to move the driving cam plate up and down in conjunction with the intermittent rotational movement of the index table;
The opening/closing member is configured to be opened below the knife edge fulcrum by the downward movement of the drive cam plate.

(Example) Next, the present invention will be described with reference to the drawings.

FIG. 1 is an overall side sectional view of a characteristic measuring unit according to an embodiment of the present invention, and FIG. 2 is an enlarged side view of portion A in FIG. 1. FIG. 3 is a schematic overall plan view of an embodiment of the present invention.
Chip capacitors, which are parts to be measured, are held at regular intervals on the outer periphery of an index table 10 that rotates intermittently.
A measurement unit housing 11 is fixed to the apparatus base 14 side so as to pass through the center of the table and cover the upper surface of the table. A disk-shaped base portion 13a of a driving cam plate 13 of an opening/closing member, which will be described later, is pivotally supported in the center of the housing 11 via a ball spline shaft 12 so as to be movable up and down. Cam plate 13 for driving the opening/closing member
A plurality of radially extend from the outer periphery of the disc-shaped base 13a as shown in FIG. Device base 14
A group of cams for driving the device is disposed inside the device, and the cam plate 13 for driving the opening/closing member is moved up and down via the cam floor, the transmission link 16, the lever 17, etc. It is also connected to the support shaft 18 of the index table 10, so that the opening/closing member driving cam plate 13 and the index table 10 operate in conjunction with each other.

Referring to FIGS. 1 and 2, an opening/closing member support plate 19 corresponds to the opening/closing member driving cam plate 13.
A plurality of capacitors are attached to the unit housing 11 radially extending to a position above the chip capacitor 1 on the outer periphery of the index table 10. A pair of opening/closing members 20 having the same shape penetrates and is supported by each opening/closing member support plate 19 .

4 is a perspective view of the opening/closing member 20, FIG. 5 is an enlarged front view taken in the direction of arrow B in FIG. 2 showing the knife edge support mechanism of the opening/closing member 20 on the opening/closing member support plate 19, and FIG. FIG. 5 is a sectional view taken along line D-D, showing the structure of a knife edge support portion between one of the opening/closing members 20 and the support plate 19. FIG. 6b is a partial top view of FIG. 6a viewed from the direction of arrow E. FIG. Each opening/closing member 20 has a cam roller 2 at its upper end.
1 is pivotally supported, and a thin plate-shaped and L-shaped measurement contact 22 is fixed to the lower end so that the tips thereof face the contact of the other opening/closing member, and furthermore, a substantially midway portion thereof is fixed. More specifically, lateral brim-shaped projecting portions 23 are formed on both sides of the opening/closing member at positions closer to the upper side, thereby forming recessed portions 24 on both sides of the opening/closing member. Overhang part 2
The lower surface of 3 is tapered in the shape of a knife edge.

As shown in FIGS. 5 and 6b, the opening/closing member support plate 19 has a hole 19a that passes vertically through the opening/closing member 20 at its support location, and a pair of opposing protrusions 25 are provided on both sides of the through hole 19a. is provided, and in a state where the opening/closing member 20 is inserted into the through hole 19a, the protruding portion 25 is inserted into the recessed portion 24 of the opening/closing member 20, thereby forming a lower edge, that is, a knife edge portion of the overhanging portion 23 of the opening/closing member 20. is supported on the upper surface of the protrusion of the support plate 19 by a contact line. In this way, the knife edge fulcrum 25a of the opening/closing member 20 is formed on the upper surface of the protrusion of the support plate 19, and the opening/closing member 20 is supported only by this knife edge fulcrum and swings in the direction of the arrow F in FIGS. 2 and 6a. The opening/closing operation is performed centering around this knife edge fulcrum 25a. In order not to interfere with the opening/closing operation of the opening/closing member 20, the lower surface 25b of the protrusion 25 is formed in an arc shape as shown in FIG.
When the opening/closing member is opened/closed, the lower surface (the fourth
(see FIG. 6A) is designed to prevent unreasonable contact with the lower surface 25b of the protrusion 25. Moreover, the opening/closing member 20 can be pulled out upward by the protruding lower surface 2.
This is prevented by the contact between 5b and the lower surface of the concave portion 24.
For manufacturing reasons, the part forming the protrusion 25 is actually the support member 1 as a knife edge fulcrum member.
This small piece (see FIG. 6b) is assembled into the through hole 19a of the support member 19. In FIG. 6b, the opening/closing member 20 is shown in broken lines for clarity.

As clearly shown in FIG. 2, a pair of brackets 26 are fixed to the opening/closing member support plate 19, and between the brackets 26 and the opening/closing member 20 at a position below the knife edge fulcrum, the opening/closing member 20 is moved in the closing direction. A compression coil spring 27 is attached to press the spring. Further, a stopper adjusting screw 28 is screwed onto the bracket 26 at a position above the knife edge fulcrum and is in contact with the opening/closing member 20 to regulate the amount of closing of the lower end or the closing limit position. 29 is a lead terminal of the L-shaped thin plate contactor 22.

The outer end of each of the radially extending opening/closing member driving cam plates 13 branches downward into a fork shape, and the inner surface thereof forms a tapered cam surface 30. When the driving cam plate 13 is lowered, the pair of cam surfaces 30 abut against the cam roller 21 at the upper end of the opening/closing member 20, and the cam roller is pushed inward, resisting the spring force of the compression spring 27 and pushing the opening/closing member 20 rotates around the knife edge fulcrum,
The L-shaped contact 22 at the lower end is opened. Note that the pair of opposing cam surfaces 30 of the drive cam plate 13, the cam roller 21, the opening/closing member 20, the compression spring 27, and the L-shaped contact 22 at the lower end are arranged symmetrically with respect to the vertical center line C between the opening/closing members. The tips of the contacts 22 are arranged so as to sandwich the chip capacitor 1 held on the outer periphery of the index table 10 from both ends thereof. Regarding the structure of the L-shaped contact, for example, the structure described in detail as an electrode for measuring characteristics in Utility Model Application No. 63-65576 can be effectively adopted. As mentioned above, a plurality of cam plates 13 for driving the opening/closing member extend radially from the center of the unit housing 11 to a predetermined measurement station position.
Correspondingly, below the opening/closing member 2 described above,
0, bracket 26, compression spring 27, adjustment screw 2
8 etc. are held in pairs on the opening/closing member support plate 19. The radially extending portion of the driving cam plate 13 and the support plate 19 are removably attached to the disk-shaped base portions 13a and 19a, respectively, by bolts or the like (FIG. 1).

Referring again to FIG. 3, the chip capacitors are sequentially supplied from the chip feeder 31 to the outer periphery of the index table 10, are held by the table, and are intermittently operated by the chip detection station located around the table and various characteristics. It moves intermittently to the measurement station, discharge station, discharge station, etc. The part 40 in FIG. 3 is a discharge station, and the chip capacitor is discharged to the outside of the table using air pressure. As for the holding mechanism for the chip capacitor, for example, a carrier for measuring characteristics disclosed in Japanese Patent Application No. 186267/1983 can be effectively employed. In conjunction with this intermittent rotation of the index table 10, the device driving cam moves the opening/closing member driving cam plate 13 to the index table 10, unit housing 11, opening/closing member support plate 19, and therefore to the opening/closing member 20. When it moves up and down, the opening/closing member 20 opens and the L-shaped contact 22 faces the moving chip capacitor 1, and when it moves up, the contact 22 closes due to the action of the compression spring 27, and the electrode of the chip capacitor 1 During the next descent, the chip capacitor 1 moves to the next station together with the index table. While repeating this operation at each measurement station, the chip capacitors are sequentially discharged from the intermediate or final discharge station 40.

In the present invention, the opening/closing member is knife-edge supported for opening/closing operation, so high-speed operation is possible. However, when operating at high speed, if the moment of inertia is large, a large impact force is applied to the small chip capacitor, and the external exposed electrodes of the capacitor are In order to reduce the moment of inertia, a hole 32 is provided in the opening/closing member as shown in FIG. 4 to prevent the opening and closing member from becoming dented, resulting in poor appearance or inferior characteristics. In the above embodiment, the chip components are moved intermittently by the index table, and the measurement units are arranged radially around the index table from the center of the table. Instead, a linear motion table that moves linearly intermittently may be used, the chip component may be held on the translation table, and the measuring units may be arranged at predetermined intervals along the translation table. Such a form also belongs to the present invention, and in either case, the opening/closing member is opened and closed simultaneously by a single movement of a plurality of opening/closing members by a drive cam plate connected at the base, and the drive system becomes extremely simple.

(Effects of the Invention) As explained above, according to the present invention, the opening/closing member opens and closes by swinging motion using the knife edge fulcrum, so the operation is very easy and fast, and the fulcrum spacing l (Fig. 2) This allows the measurement contact at the bottom to move in a nearly straight line (horizontal).
The chip touches and separates perpendicularly to both end faces of the chip, and there is no uneven contact or slanted contact, allowing for highly accurate measurements. Unlike conventional linear guides or shaft rotation supports, there are no sliding parts, and it can be easily attached and detached depending on the required station. Depending on the size of the target chip part, the closing position and opening/closing amount of the contact (measuring head) can be easily set by operating the adjustment screw. The contact pressure (measured pressure) is provided by the spring force of the compression spring, so it remains constant, and this contact pressure can be easily changed by replacing the spring, which provides many advantages over conventional methods.

[Brief explanation of the drawing]

FIG. 1 is an overall side sectional view of a characteristic measuring unit according to an embodiment of the present invention, FIG. 2 is an enlarged side view of part A in FIG. 1, and FIG. 3 is a schematic diagram of an embodiment of the present invention. 4 is a perspective view of the opening/closing member used in the present invention, FIG. 5 is a front view of the knife edge support mechanism of the opening/closing member, and FIG. 6a is D-D in FIG. 5.
A cross-sectional view along the line, FIG. 6b is in the direction of arrow E in FIG. 6a.
7 is a schematic diagram showing the state of capacitance measurement of a chip capacitor using the conventional one-side contact method, and FIG. 8 a, b, and c are schematic diagrams of measurement contacts using the conventional opposing contact method. , FIG. 9 is a schematic diagram of a conventional facing contact type contact having a shaft support structure using a fulcrum pin. DESCRIPTION OF SYMBOLS 1... Chip capacitor, 10... Index table, 11... Unit housing, 12... Ball spline shaft, 13... Cam plate for driving opening/closing member,
19... Opening/closing member support plate, 20... Opening/closing member, 22...
Measuring contact, 28...adjustment screw, 30...cam surface.

Claims (1)

[Scope of Claims] 1. A cam plate for driving an opening/closing member disposed above an intermittent moving table that holds an object to be measured and pivotally supported to move up and down with respect to the table; a drive mechanism, an opening/closing member support plate disposed between the drive cam plate and the intermittent movement table and fixed to the apparatus main body side, and a part extending through the opening/closing member support plate and having an intermediate portion thereof. a pair of opening/closing members which are supported in a knife edge manner and have a measuring contact at their lower ends; and a pair of opening/closing members disposed below the knife edge fulcrum of the opening/closing members and biasing the opening/closing members in a direction in which the lower ends of the opening/closing members are closed. and a cam portion provided at the tip of the opening/closing member driving cam plate and tapered into engagement with the upper end of the opening/closing member, The chip is configured to move the driving cam plate up and down in conjunction with the intermittent feeding motion of the moving table, and the lower side of the knife edge fulcrum of the opening/closing member is opened by the downward movement of the driving cam plate. Capacitor characteristic measurement unit. 2. Characteristics of the chip capacitor according to claim 1, characterized in that the opening/closing member support plate is provided with an adjustable stopper member for regulating the amount of closing rotation of the opening/closing member at a position above the knife edge fulcrum. measurement unit.