JP2926529B2 - Print head for wire dot printer - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial applications]

The present invention relates to a print head for a wire dot printer.

[0002]

2. Description of the Related Art Wire dot printers are used for printing on a plurality of stacked forms because of their high printing pressure, and are classified into release type, suction type, piezo type and the like according to the driving method.

[0003] The release type is, for example, as shown in FIG. 1, a pin lever 2 is swingably supported by a base 1 via a leaf spring 6, and a wire ( By fixing the base end of the dot pin 3, the pin lever 2 is restrained to the retracted position by the permanent magnet 7 against the leaf spring 6, and the magnetic field of the permanent magnet 7 is eliminated by the magnetic field of the degaussing coil 8, thereby 2 and the wire 3 are projected to the printing position by the force of the leaf spring 6.

Although not shown, the suction method is such that a pin lever is swingably supported by a base via a leaf spring, and a base end of a wire extending in the swing direction of the pin lever is fixed to the tip of the pin lever. It refers to a system in which a pin lever and a wire urged to a standby position by a leaf spring are attracted from the standby position to a printing position by an electromagnet for printing.

Although not shown, the piezo method is
The pin lever is swingably supported on the base via a leaf spring, the base end of a wire extending in the swing direction of the pin lever is fixed to the tip of the pin lever, and the pin lever urged to the standby position by the leaf spring stands by. A piezo element having a plurality of piezo elements which are driven from a position to a printing position and printing is performed by an electrostrictive action of the piezo element.

In these wire dot printers, a pin guide 4 through which the tip of each wire 3 is inserted is fixed to the base 1 so that the printing position does not change. In general, a sintered high-speed material is used for the wire 3 in order to reduce cost and weight, and a synthetic resin such as polyacetal is used for the pin guide 4, for example.

[0007]

The wire 3 made of the sintered high-speed material as described above has elasticity, and the base end and the pin of the wire 3 are reacted by the wire 3 being hit against the ink ribbon running in front of the paper. It is known that a portion inserted into the guide 4 vibrates as a node. This vibration increases as the wire length increases, and the wire length increases by 15 m.
If m is exceeded, the vibration may cause the wire to become fatigued and broken.

For example, a wire diameter of about 0.3 mm, a wire length of 5
In the case of a wire of about 0 mm, the amplitude becomes 0.6 mm or more, and becomes larger than 0.4 mm which is considered to be a limit value. For example, breakage of the wire frequently occurs at about 20 to 30 million strokes.

Therefore, an attempt was made to reduce the amplitude of the intermediate portion of the wire 3 by supporting a guide for inserting the intermediate portion of the wire 3 on the base 1. Pulled laterally,
On the contrary, excessive force may act on the wire 3,
It was found that breakage of the wire 3 could not be effectively prevented.

The present invention has been made in view of the above circumstances, and has as its object to provide a print head of a wire dot printer capable of preventing breakage of a wire.

[0011]

According to the present invention, as shown in FIG. 1, for example, a plurality of pin levers 2 are supported on a base 1 so as to be swingable. In order to achieve the above object, assuming a print head of a wire dot printer in which a base end of the extending wire 3 is fixed and a guide 4 through which a distal end of each wire 3 is inserted is supported by the base 1, We have taken such measures.

That is, the vibration damping member 5 into which the wire 3 is inserted between the pin lever 2 and the pin guide 4 is attached to the base 1.
It provided to be floating within a predetermined range with respect Rutotomoni, upper
A protrusion where a wire slides on one or both surfaces of the vibration damping member 5
An edge 4a is formed.

Further, a projection 4a with which the wire 3 comes into sliding contact.
Is to be formed on one or both sides of the pin guide 4
Is also possible.

[0014]

[Operation] The vibration damping member 5 of the present invention can be provided at one ratio for one wire 3 or at one ratio for a plurality of wires 3.

[0015] 1 when the wires 3 with respect to providing a vibration-damping member 5 in a ratio of one is certain height, i.e., member vibration system that have a predetermined dimension in the longitudinal direction of the wire 3 5, the amplitude of the wire 3 is suppressed within the elastic deformation region by limiting the deflection of the wire 3 to a certain value or less on the inner peripheral surface of the vibration damping member 5 between the heights.

When one vibration damping member 5 is provided for a plurality of wires 3, the vibration of one wire 3 is received by another wire 3 via the vibration damping member 5. The maximum amplitude of the wire 3 is suppressed within the elastic deformation region.

By forming the projection 4a on the vibration damping member 5 or the pin guide 4, when the amplitude of the wire 3 spreads uniformly, the wire 3 is received by the projection 4a and the amplitude is prevented from further expanding. Is done.

[0018]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be specifically described below with reference to the drawings. FIG. 1 is a front view of a print head of a wire dot printer according to an embodiment of the present invention. This print head has an upper unit U1 and a lower unit U2 which are vertically overlapped, and each of the units U1 and U2 has 12 print heads. In total, a total of 24 wires 3 are provided.

The wires 3 of each of the upper and lower units U1 and U2 are arranged in two columns on the left and right and six rows before and after, and the position of the wires 3 of the upper unit U1 and the position of the lower unit U2 are slightly forward and backward in plan view. Are staggered.

Each print head is of the release type, and the same number of lower spacers 1 a as
The leaf spring 6, upper spacer 1b, magnetic block 1c, permanent magnet 7, and core 1d are fixed together by screws.

As shown in the cross-sectional view of FIG. 2, the distal end side of each magnetic block 1c is formed in a bifurcated shape, and the base end is lowered via a support wire 9 between the fore ends of the magnetic block 1c. An armature 10 supported by the side block 1a and fixed to the upper surface of the distal end of the leaf spring 6 is arranged. The pin lever 2 is fixed to the tip of the armature 10, and the base end of the wire 3 is fixed to the tip of the pin lever 2.

The tip of the core 1 d is
It is hung downward facing 0, and the degaussing coil 8 is wound around this hung portion (coil core). In this print head, a magnetic field surrounding the upper spacer 1d, the magnetic block 1c and the core 1d is formed by each permanent magnet 7, and each armature 10 is attracted to the core coil against the leaf spring 6 by this magnetic field. The wire 3 is restrained at the standby position. Then, a current is applied to the demagnetizing coil 8 to form a magnetic field for eliminating the magnetic field, thereby releasing the armature 10 from the magnetic attraction force of the permanent magnet 7 and advancing to the printing position by the force of the leaf spring 6. .

A pin guide 4 having a guide hole through which each wire 3 is inserted is fixed to each of the upper and lower bases 1 in order to restrict the position of the wire 3 and secure the printing position accuracy. However, as shown in detail in the cross-sectional view of FIG. 3, a plate-shaped or block-shaped vibration damping member 5 having a guide hole into which each wire 3 is inserted above the lower base 1 is within a certain range. It is movably supported by.

The pin guides 4 and the damping members 5 are
In order to reduce the sliding resistance of the wire 3, the wire 3 is made of a synthetic resin such as polyacetal which is rich in surface lubricity and abrasion resistance.

In this embodiment, when the amplitude of the vibration of the wire 3 due to the printing reaction force reaches a certain value, the vibration of the wire 3 is received by the other wire 3 via the vibration damping member 5 and the other wire 3 is received. The elasticity of 3 prevents the amplitude from being expanded beyond a certain level. As a result, the amplitude of the wire 3 was suppressed within the limit of elastic deformation, and breakage of the wire 3 did not occur even if the amplitude exceeded, for example, 500 million strokes.

Then, as shown by a virtual line in FIG.
The wire 3 slides on one or both sides of the vibration damping member 5
By forming the projection 4a, the effect of the vibration damping member 5 can be reduced.
It is possible to further increase.

It should be noted that in this embodiment, left and right opposing arrangements are provided.
The wire 3 of the print head to be inserted into one damping member 5
But the print heads that overlap vertically
Wire 3 can be inserted into one damping member 5
Noh.

FIG . 4 shows a mark according to another embodiment of the present invention.
FIG. 4 is a cross-sectional view of a main part of a character head, in this embodiment,
A projection 4 is provided on the upper surface of the pin guide 4 fixed to the base 1a.
a of the wire 3 inserted into the guide hole 4b.
In addition to reducing the contact pressure to the guide hole 4b, the wire 3
The amplitude of the wire 3 is kept at a certain
I try to limit it below.

The projections 4a are independent for each wire 3.
Although it may be formed in a dot shape, a plurality of wires arranged in a predetermined direction
If it is formed in a continuous strip shape over the layer 3, the projections 4a
Plays the role of reinforcing the pin guide 4 with a thickness of less than 1 mm.
However, distortion (warpage) of the pin guide 4 during molding,
If the pin guide 4 is warped due to temperature rise during operation of the device,
This is advantageous because generation can be prevented.

[0030]

As described above, according to the present invention,
Is provided so as to be movable within a certain range with respect to the base.
By inserting the middle part of the wire through the damping member,
In addition to suppressing the vibration of the ear via the damping member,
Wire on the protrusion provided on the vibration control member or pin guide
Contact, the vibration of the wire due to the printing reaction force
The width can be kept within the limits of its elastic deformation,
Thus, breakage of the wire can be prevented.

[Brief description of the drawings]

FIG. 1 is a front view of a printing unit according to an embodiment of the present invention.

FIG. 2 is a sectional view of a print head according to one embodiment of the present invention.

FIG. 3 is a sectional view of a main part of a print head according to one embodiment of the present invention.

FIG. 4 shows a print head according to another embodiment of the present invention .
It is sectional drawing of a principal part.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Base 2 Pin lever 3 Wire 4 Pin guide 4a Projection 5 Damping member

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-53-135724 (JP, A) JP-A-52-152320 (JP, A) Fully open 1979-151412 (JP, U) Really open 1980 166654 (JP, U) (58) Fields surveyed (Int. Cl. ⁶ , DB name) B41J 2/265 B41J 2/275-2/28

Claims (2)

(57) [Claims] A plurality of pin levers (2) are swingably supported on a base (1), and a pin lever is provided at the tip of each pin lever (2).
A wire dot where the base end of the wire (3) extending in the swing direction of (2) is fixed, and the base (1) supports a pin guide (4) through which the tip of each wire (3) is inserted. In the print head of the printer, wire between the pin lever (2) and the pin guide (4).
(3) Rutotomoni provided to be floating within a predetermined range with respect to the base body (1) a vibration damping member is inserted (5), the vibration damping member
(5) One or both sides of the wire (3) slides on the protrusion (4
A print head for a wire dot printer, characterized in that a) is formed . 2. A plurality of pin levers (2) are oscillated on a base (1).
As far as possible, and attach a pin lever to the end of each pin lever (2).
Fix the base end of the wire (3) extending in the swing direction of (2)
Then, the pin through which the tip of each wire (3) is inserted into the base (1)
Of the wire dot printer supporting the guide (4)
In the print head, wire (3) is provided on one or both sides of the pin guide (4).
A wire formed with a protrusion (4a) that comes into sliding contact
Print head for dot printer .