JP4655953B2 - Controller - Google Patents

Description

  The present invention relates to an insulating structure for a controller having a high-voltage circuit component.

  In recent years, the density of circuit assemblies using surface mount components has been increasing, and the electronic components mounted on the circuit board and the solder connection portions are stored in a resin case with consideration given to preventing stress from being applied.

  Conventionally, in a high-voltage electronic component unit in which a circuit board equipped with high-voltage electronic components is housed in a synthetic resin insulation case, insulation can be performed while the variable resistor can be rotated from the outside in order to reliably increase the withstand voltage. A double structure has been proposed for the purpose of reinforcement (for example, see Patent Document 1).

  On the other hand, in a controller equipped with a variable resistor that is operated from the outside, for example, a controller that variably controls the motor speed for industrial use, a high voltage is applied to the variable resistor. After screwing onto the metal shaft, removal is prohibited by a blindfold seal.

There is a possibility that an external force may be applied to the operation knob in the axial direction, and the external force is not directly applied to the circuit board by screwing the variable resistor to the resin case.
JP-A-8-51006

  The problem to be solved by the present invention is that the operation knob may be removed, and if the knob is removed while the power is on, the metal shaft is exposed and there is a possibility of electric shock.

  As a countermeasure, the shaft of the variable resistor may be changed from metal to resin. However, the screw fixing strength of the knob and shaft is insufficient, and the screw fixing part to the resin case is still exposed from the outside. Countermeasures are necessary.

  In order to ensure a structure that cannot be easily disassembled and to prevent electric shock of the variable resistor, there is a problem that the structure becomes complicated and the assembly work becomes complicated.

  The present invention solves the above-described conventional problems, is easy to assemble, and there is no worry of electric shock even if the operation knob is removed, no external force is directly applied to the circuit board, high reliability and good operability control. The purpose is to provide a vessel at low cost.

In order to solve the above-described conventional problems, the present invention provides a controller in which a high-voltage unit can be touched from the outside of a resin case when an operation component is removed, and a high-voltage circuit component mounted on a circuit board; A resin case, a resin panel that is engaged and fixed on the surface of the resin case and covers the exposed high voltage portion, and a knob that operates the high voltage circuit component from the outside of the panel. Has a cylindrical projection and a claw that pivotally engages with the resin case in a disc-shaped flange, and the projection is disposed radially with respect to the inside of the knob via a gap. The controller is characterized in that when an external force in the axial direction is applied to the knob, no external force is directly applied to the high-voltage circuit component due to the contact configuration between the inner bottom portion of the knob and the end face of the protrusion.

  Further, the resin case has a hole portion that is pivotally engaged with the claw portion of the panel, and an inclined projection portion on the inside while moving from the start to the end of the rotation, and is assembled by the engagement of the inclined projection portion and the claw portion. The stopper function that can not be returned to the original position by reverse rotation of.

  According to the controller of the present invention, the resin case and the panel are pivotally fixed so that the assembly operation is easy, but the external force in the axial direction applied to the operation unit is not directly applied to the circuit board, and the circuit board is mounted with high density. The reliability of the solder connection portion can be ensured.

  Further, since the stopper function is exhibited by the engagement between the claw portion of the panel and the inclined projection portion of the resin case, it cannot be turned in the reverse direction after being fixed, so there is no fear of disassembly.

  Moreover, since the shaft of the variable resistor is made of resin, there is no fear of electric shock even if the operation knob is removed.

  Further, by providing a stepped surface on the resin case, only a person who knows the disassembling method can remove the panel after turning and fixing, so that the maintenance work becomes easy.

  Furthermore, in the case of a controller (speed controller) that controls the rotational speed of the motor, by displaying a scale on the outer surface of the collar, the positional relationship between the scale and the mark displayed on the knob becomes easy, and the rotational speed It can be used as a guide and improves usability.

  Thus, no external force is directly applied to the circuit board via the high-voltage circuit component, and no electric shock is generated even if the operation knob is removed. Furthermore, since the panel cannot be simply turned in the reverse direction, it is not generally disassembled, and only a person who knows the disassembly method can perform the maintenance work. Therefore, a highly reliable controller can be provided at low cost.

  A high voltage circuit component mounted on a circuit board; a resin case that houses the circuit board; a resin panel that is engaged and fixed on the surface of the resin case by rotation and covers the exposed high voltage portion; and the high voltage circuit component A knob that is operated from the outside of the panel, and the panel has a cylindrical projection and a tab that pivotally engages with the resin case in a disc-like flange portion, and the projection is formed inside the knob. When an external force in the axial direction is applied to the knob in the radial direction, no external force is directly applied to the high-voltage circuit component due to the contact structure between the inner bottom of the knob and the end face of the protrusion. The high-voltage circuit component is a variable resistor whose shaft is made of resin, and the resin case has a hole that swivels and engages with the tab of the panel, and the slanted protrusion inside the swivel start to finish The inclined projection part By engagement of the claw portion, in the reverse turning at the time of assembly to exert a stopper function that can not be returned to its original position.

  FIG. 1 is a cross-sectional view of the main part of the controller of the present invention. In FIG. 1, 1 is a variable resistor for high-voltage circuit components, 2 is a circuit board, 3 is a resin case, 4 is a resin panel, and 5 is a resin. It is a made knob.

  The shaft 1a of the variable resistor 1 is made of resin, and is mounted so that the shaft 1a is parallel to the circuit board 2 and exposed to the outside from the resin case 3, and can be operated from the outside.

  A circuit board 2 on which circuit components including the variable resistor 1 are mounted is housed in a resin case 3 and fixed with screws. Thereafter, the claws 4a are inserted into the holes provided in the resin case 3 so that the panel 4 is covered with the shaft 1a, and engaged and fixed while turning. Furthermore, the D-cut part of the shaft 1a and the hole position of the knob 5 are matched, and the knob 5 is mounted.

  At this time, the projection 4b end surface of the panel 4 is in contact with the inner bottom 5a before the tip of the shaft 1a contacts the inner bottom 5a of the knob 5, and an axial external force is applied to the knob 5. However, an external force is not applied to the resin case 3 from the panel 4 and the external force is not directly applied to the circuit board 2 via the variable resistor 1, so that the reliability of the solder connection portion of the circuit board 2 can be ensured. .

  Next, a configuration in which the panel 4 can be engaged and fixed to the resin case 3 by turning, but cannot be disassembled by reverse turning will be described with reference to FIG.

  FIG. 2 is a view of the resin case 3 as viewed from the knob mounting side, and two L-shaped hole portions 3a that are pivotally engaged with the claw portions 4a of the panel 4 are provided at two positions 180 degrees apart. A stepped surface 3b is formed around the hole 3a by one step from the surface of the resin case, and the reason will be described later. In the center, a shaft 1a of the variable resistor 1 and a square hole through which the threaded portion passes are provided. Further, while the claw portion 4a of the panel 4 moves from the turning start to the end, the inclined protrusion 3c (FIG. 1). Is provided on the inside.

  On the other hand, as shown in FIG. 3, the panel 4 is provided with two claw portions 4 a and a cylindrical projection 4 b in a disc-shaped flange portion 4 c, and the claw portion 4 a on the inner side with respect to the resin case 3. The protrusion 4b is provided on the outside. Further, the claw portion 4a is provided with a small protrusion 4d having a semicircular cross section extending in the radial direction. In addition, a part of the inner diameter of the protruding portion 4b is made small so that the high voltage portion of the variable resistor 1 is not exposed, and the outer diameter of the protruding portion 4b is set so as to secure a gap with the inside of the knob 5. Yes.

  Here, engagement fixation and release of engagement fixation by turning the resin case 3 and the panel 4 will be described with reference to FIG.

  First, when the claw portion 4a of the panel 4 is inserted into the hole 3a of the resin case 3 and turned, the protrusion 4d of the claw portion 4a moves over the inclined protrusion 3c while moving from the smaller inclination to the larger one, and the stopper function is achieved. Demonstrates engagement and fixing.

  Even if the panel 4 is to be rotated in the engaged and fixed state, the claw 4a (projection 4d) cannot easily get over the inclined projection 3c, and the panel 4 is not detached from the resin case 3.

  Even when the knob 5 is removed in the engaged and fixed state, the inner diameter portion of the protruding portion 4b is formed so as to cover the high voltage portion of the variable resistor 1, and there is no fear of electric shock.

  Next, a method for releasing the engagement and fixation will be described. As described with reference to FIG. 2, the resin case 3 is provided with the step surface 3 b formed by digging the periphery of the hole 3 a one step, and is rotated in the reverse direction using this step.

In other words, when the two portions of the flange portion 4c of the panel 4 on the step surface 3b in the vicinity of the inclined projection portion 3c are pushed into the inside (arrow) of the resin case 3, the flange portion 4c and the tab portion 4a are separated by a step. Only the inside of the resin case 3 bends, and the stopper function by the protrusion 4d and the inclined protrusion 3c is released. When reversely rotated in the released state, the protrusion 4d of the panel 4 is inclined to the inclined protrusion 3c of the resin case 3.
Therefore, the panel 4 can be removed from the resin case 3.

  Note that if the knob 5 is removed, an external force may be applied to the shaft 1a of the variable resistor 1. Therefore, the screw is fixed so that the resin case 3 is sandwiched by using the fixing screw of the variable resistor 1. It is safer.

  Further, as shown in FIG. 5, when the controller is a speed controller that variably controls the rotation speed of the single-phase induction motor, the outer diameter of the flange 4c of the panel 4 is set larger than the knob 5, and the surface of the flange 4c If a scale is provided in, it can be used as a guide for the rotation speed, and the operability is improved.

  Although the variable resistor of Example 1 was a type in which the shaft was parallel to the circuit board, the position of the hole provided in the resin case can be changed even if the shaft is a type perpendicular to the circuit board. Can be implemented in the same manner.

  The controller of the present invention is useful for a controller equipped with a high-voltage circuit component operated from the outside, for example, an electric motor controller for industrial use.

Sectional drawing of the principal part of the controller in Example 1 of this invention The top view of the resin case in Example 1 of this invention Sectional drawing of the panel in Example 1 of this invention Explanatory drawing of the panel attachment / detachment method in Example 1 of this invention. The perspective view of the controller which removed the knob in Example 1 of this invention

Explanation of symbols

1 High-voltage circuit components (variable resistors)
DESCRIPTION OF SYMBOLS 1a Shaft 2 Circuit board 3 Resin case 3a Hole part 3b Step part 3c Inclined protrusion part 4 Panel 4a Claw part 4b Protrusion part 4c Lump part 4d Protrusion 5 Knob

Claims (5)

In a controller in which the high-voltage part can be touched from the outside of the resin case when the operation parts are removed, the high-voltage circuit component mounted on the circuit board, the resin case for storing the circuit board, and the surface of the resin case A resin panel that covers and exposes the high-voltage part that is engaged and fixed, and a knob that operates the high-voltage circuit component from the outside of the panel. The panel swivels with the cylindrical protrusion and the resin case. When the disc-shaped flange portion has an engaging claw portion and the projection portion is disposed through a gap in the radial direction with respect to the inside of the knob, and an external force in the axial direction is applied to the knob The controller is characterized in that an external force is not directly applied to the high-voltage circuit component due to the contact structure between the inner bottom portion of the knob and the end surface of the protrusion. The resin case has a hole portion that is pivotally engaged with the claw portion of the panel, and an inclined protrusion portion on the inside during the movement from the start to the end of the rotation, and the assembly is reversed by the engagement of the inclined protrusion portion and the claw portion. The controller according to claim 1, which exhibits a stopper function that cannot be returned to its original position by turning. 3. The high-voltage circuit component according to claim 1 or 2, wherein the shaft is a resin-made variable resistor, the outer diameter of the flange portion of the panel is set larger than the outer diameter of the knob, and a scale is displayed on the outer surface of the flange portion. Controller. By providing a step surface dug down around the hole on the outside of the resin case, and pushing the collar portion of the panel on the step surface inward of the resin case, the stopper function by the claw portion and the inclined protrusion is released, The controller according to claim 2 or 3, wherein the panel is removed from the resin case by reversely turning in the released state. The controller according to any one of claims 1 to 4, wherein the rotational speed of the single-phase induction motor is varied by varying a resistance value of a variable resistor that is a high-voltage circuit component.

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