JPH0118357Y2 - - Google Patents

Description

[Detailed Description of the Invention] This invention relates to the structure of a needle holding arm in a needle dot printer.

A needle dot printer prints dots by momentarily swinging an arm supported by a spring member using a solenoid, and causing a needle fixed to the tip of the arm to impact printing paper on a platen. However, in order to increase the printing speed, it is necessary to reduce the inertial mass of the arm as much as possible, so it is possible to make the arm smaller and its structure lighter without sacrificing the necessary rigidity. requested.

Conventionally, this arm structure was made of a metal plate with an H-shaped cross section (for example,
(Koan No.), or those formed into a box shape (for example, the invention of Tohokukai No. 54-92822), etc. However, the H-shaped cross section has a problem in terms of torsional rigidity, and the box shape The drawback was that the manufacturing cost was high. The object of this invention is to obtain an arm that has sufficient bending and torsional rigidity and can be manufactured lightweight and inexpensively.

That is, the needle holding arm of this invention includes a rectangular or elongated triangular core, a thin metal plate fixed to both sides of the core and whose distal and proximal ends extend from the core, and both metal plates. and a movable iron core, the connecting portion of which is clamped and fixed between the proximal extending portions of both metal plates. The present invention will be described in detail below based on the embodiments shown in the drawings.

Figures 1 and 2 show the first embodiment of this invention, in which 1 is an elongated triangular core, 2 and 2 are thin metal plates glued to both sides of this core, and 3 and 3 are thin metal plates glued to both sides of the core.
is an extension of the tip of the metal plate 2; 4, 4 is an extension of the proximal end of the metal plate 2; 5 is a tubular needle holding member clamped and fixed between the extensions 3; 6 is an extension. This is a movable iron core whose connecting portion 7 is sandwiched and fixed between 4 and 4.

The core 1 is made of synthetic resin reinforced with carbon fiber, boron fiber, etc., which has a smaller mass than metal,
Its thickness (dimension in the left-right direction in FIG. 1) is about 3 to 4 mm. The metal plate 2 is, for example, a stainless steel plate, a nickel or titanium alloy plate, etc.
It has a thickness of about 0.2 mm, and has a distal end extending portion 3 and a proximal extending portion 4 that are joined to both sides of the core 1 and protrude from the core 1. The needle holding member 5 has a through hole 9 in which the needle 8 (FIG. 4) is inserted in the shaft center, and the metal plate 2 is held between the tip extension portions 3 of the metal plate 2. is joined to. Through hole 9
is at least on the needle 8 installation side (left side in Figure 1)
The proximal end of the needle 8 is inserted into the through hole 9 and fixed by welding, caulking, or other means.
As shown in FIG. 4, the movable core 6 is held by a stationary member via a spring plate 10 fixed to the movable core 6.
The arm is attracted and separated from the fixed core 13 by the magnetic force of the permanent magnet 11 and the solenoid 12, and swings the arm.
It is joined to the metal plate 2 while being held in between.

FIG. 4 shows this arm 14 along with an example of its drive mechanism. The drive mechanism shown is of a release type, in which the movable core 6 is attracted to the fixed core 13 by the magnetic force of the permanent magnet 11. In this state, the needle 8 is held at the standby position, and at a predetermined timing, the solenoid 12 is demagnetized to cancel the magnetic force of the permanent magnet 11, and the arm 14 is swung by the elasticity of the spring plate 10, so that the needle 8 is rotated. One dot is printed on the printing paper on the platen by impacting the platen (not shown), demagnetizing the solenoid 12, and causing the bounced movable core 6 of the arm 14 to be attracted to the fixed core 13 again. be.

As shown in FIG. 3, the arm 14 configured as described above has a core material 16, an iron core material 17, and a large number of needle holding members 5...5 held at predetermined positions between two metal plates 15, 15. By producing a bonded semi-finished product 18 and cutting it using a laser cutting machine at the position indicated by the imaginary line in the figure, it can be easily and inexpensively manufactured. And this arm 14
are a core 1 and metal plates 2 bonded to both sides of the core 1,
2, it has high bending and torsional rigidity, and depending on the material of the core 1, it is possible to reduce the weight.

5 and 6 show a second embodiment of this invention, in which metal plates 2 are bonded to both sides of the core 1.
By bending the side wall portion 19, higher rigidity is imparted. This second
Since it is impossible to manufacture the product of this embodiment by cutting a semi-finished product as shown in FIG. 3, it is more expensive than the product of the first embodiment, but it has higher rigidity. Because of this structure, the arm can be made smaller and can be manufactured at a much lower cost than the conventional box structure.

As explained above, the needle holding arm of this invention is lightweight, has high rigidity, and can be manufactured at low cost. This has the effect that a needle-type printing head capable of printing can be provided at low cost.

[Brief explanation of the drawing]

Figures 1 to 4 show the first embodiment of this invention, with Figure 1 being a side view of the arm, Figure 2 being a front view of the arm, and Figure 3 showing the half of the arm being manufactured. FIG. 4 is a perspective view showing the product, and FIG. 4 is a side view showing the arm and its drive mechanism. 5 and 6 show a second embodiment of this invention, with FIG. 5 being a front view and FIG. 6 being a plan view seen from the arm tip side. In the figure, 1 is a core, 2 is a metal plate, 3 is a tip extension part, 4 is a base extension part, 5 is a needle holding member, 6
is a movable core, 7 is a connecting part of the movable core, 8 is a needle, 9 is a through hole, 10 is a spring plate, 11 is a permanent magnet,
12 is a solenoid, and 13 is a fixed core.

Claims (1)

[Claims for Utility Model Registration] 1. A rectangular or elongated triangular core 1, a thin metal plate 2 joined to both sides of the core, and whose distal end 3 and proximal end 4 extend from the core;
A needle holding member 5 is sandwiched and fixed between the distal end extension portions 3, 3 of both metal plates, and a movable iron core whose connecting portion 7 is sandwiched and fixed between the proximal end extension portions 4, 4 of the two metal plates. A dot printer needle holding arm consisting of 6 and 6. 2. The needle holding arm according to claim 1, wherein the core 1 is made of fiber-reinforced synthetic resin.