JPH0531924A - Assembling method for print head device - Google Patents

Abstract

PURPOSE:To improve print quality without creating a clearance between a stopper on an arm side and a stopper on a support side which is allowed to come in contact with a printing wire during the return of the wire when the wire is moved forward and backward by displacement of a piezoelectric element by application of a voltage. CONSTITUTION:A piezoelectric element 5 is assembled in a support frame 6, then the first leaf spring 12 and the second leaf spring 13 are junctioned and fixed to a main support part 6a and a variable element respectively, and an arm 8 is junctioned to the connection part of both leaf springs 12, 13. Before fixing a stopper on the support side 16 is fixed to an auxiliary support part 6b, a piezoelectric element 5 is driven with a specified printing gap, and the stopper on the support side 16 is fixed with the arm 8 standing still and with its tip 8 ascending as high as it can.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a dot impact type print head device in which a piezoelectric element is expanded and contracted by applying a voltage, and the expansion and contraction movement is transmitted to a print wire which is printed toward a print medium such as paper. The present invention relates to a method of assembling.

[0002]

2. Description of the Related Art The present applicant has previously filed Japanese Patent Application No. 3-10494.
No. 0 proposed the following configuration. That is, FIG.
As shown in FIG. 3, the print head is composed of a head body 1 having a substantially circular shape in front view and a cylindrical cover 2 covering the back surface thereof, and a nose portion 3 is projected at the center of the front surface of the head body 1. A plurality of printing units 4 are radially arranged in the head body 1. Each printing unit 4 is mounted on the front end of the piezoelectric element 5 and is formed by laminating piezoelectric ceramics in a laminated manner, and is attached to the front end of the piezoelectric element 5 to expand the expansion and contraction motion of the piezoelectric element 5 and transmit it to the print wire. And a support frame 6 that extends rearward from the back surface of the head body 1 to support the printing mechanism 9 and the piezoelectric element 5. The support frame 6 is integrally formed in a U-shape by a main strut portion 6a, a sub strut portion 6b, and a rear end portion 6c so as to surround both sides in the longitudinal direction and the rear end portion of the piezoelectric element 5.

The printing mechanism 9 converts the expansion and contraction of the piezoelectric element 5 into the swinging motion of the arm 8 so that the amount of forward / backward movement of the printing wire 7 attached to the tip of the arm 8 is enlarged. For the printing mechanism 9 for this purpose, an Eden spring composed of two parallel leaf springs is used. That is, the first plate spring body 12 and the second plate spring body 13 are connected to the rigid connecting portion 10.
One end of the is connected integrally, so that it is connected in a so-called Π (Greek letter pie) shape in a side view. The base end of the first leaf spring body 12 is brazed and fixed to one side surface of the main strut portion 6a, while the base end of the second leaf spring body 13 is also brazed to the mover 14 attached to the front end of the piezoelectric element 5. It sticks. And
The extending direction of the first leaf spring body 12 and the second leaf spring body 13 is parallel to the extending direction of the printing wire 7,
It is set in the opposite direction.

Further, reference numeral 20 is a four-bar linkage mechanism member provided across the mover 14 and the sub strut portion 6b.
The node link mechanism member 23 is made of an elastic member such as a spring plate, and the wide side plate portions 23a, 23a have a notch hole 21 having an H shape in a side view, and each wide side plate part 23a sandwiching the notch hole 21. , 23a are brazed and fixed to the mover 14 and the sub strut portion 6b, respectively, and the wide side plate portions 23 are expanded and contracted by expanding and contracting the piezoelectric element 5.
The movable elements 14a and 23a are elastically deformed to have a parallelogram shape in a side view so that the movable element 14 can move in parallel with the longitudinal direction of the positionally fixed sub-column portion 6b.

In the above-mentioned prior art, when the piezoelectric element 5 extends in the longitudinal direction due to the application of voltage, the base end of the piezoelectric element 5 is fixed to the rear end portion 6c of the support frame 6, resulting in a mover. Push up 14. This allows
The first and second leaf spring bodies 12, which are attached to the main column 6a side, are set so that the upper and lower midway portions of the first leaf spring body 12 serve as rotation centers.
The connecting portion 10 at the tip of 13 is rotationally displaced in the direction of arrow A. As a result, the print wire 7 on the distal end side of the arm 8 is fixed to the nose portion 3
It moves forward toward the front surface of the platen 30. When the voltage application to the piezoelectric element 5 is released, the piezoelectric element 5 contracts and the tip end side of the arm 8 retracts from the nose portion 3 by the restoring force of the elastic deformation of the two leaf spring bodies 12 and 13.

An arm-side stopper 15 is provided on the back surface of the arm 8 in a stationary state, and a supporting-side stopper 16 is provided at the front end of the sub strut portion 6b so that the piezoelectric element 5 is in a stationary state without applying a voltage. Further, the support side stopper 16 is adjusted and fixed so as to regulate the retracted position of the arm 8. In this case, in the above-mentioned prior art, the arm-side stopper 1 in which the front surface (contact surface) of the support-side stopper 16 to be mounted on the auxiliary column portion 6b is attached to the lower surface of the arm 8.
5 is pressed while making contact with 5, and the support side stopper 16 or the arm side stopper 15 is fixed with an adhesive so that the tip side (printing wire 7 side) of the arm 8 in the stationary state and the retracted position slightly advances. To do.
Thereby, the damping of the free vibration of the arm 8 after the voltage is applied to the piezoelectric element 5 is promoted, and the printing quality is improved.

[0007]

By the way, in the above-mentioned prior art, the piezoelectric element 5 extends in its longitudinal direction when charged by applying a voltage, and the piezoelectric ceramics are laminated in multiple layers on a plane perpendicular to the extending direction. Therefore,
Conversely, when a voltage is applied to discharge, the piezoelectric element contracts in its longitudinal direction (the direction perpendicular to the stacking direction). In order to prevent the laminated portion from peeling off due to this contraction, the movable element 14 and the piezoelectric element 5 are not fixed (adhered), but the spacer (contact portion) 31 and the piezoelectric element 5 that are simply fixed to the lower surface of the movable element 14 are not separated. The spacers (contact portions) 32 fixed to the upper surface are inserted so as to come into contact with each other in a pressed state.

Therefore, as in the above-mentioned prior art, the support side stopper 16 and the arm side stopper 15 are made by slightly moving the tip end side (printing wire 7 side) of the arm 8 in the stationary state and in the retracted position forward. The following problems occurred only by fixing after positioning. That is, when the retracted position of the arm 8 in a stationary state is simply regulated by the stoppers 15 and 16 (when the print wire 7 at the tip of the arm 8 is slightly advanced), if the retracted amount of the arm 8 is too small, the arm 8 moves. The pressing force between the spacer 31 of the child 14 and the spacer 32 of the piezoelectric element 5 is insufficient. When the piezoelectric element 5 is driven (expanded and contracted) in this state, the tip of the piezoelectric element 5 is separated from the mover 14 when the piezoelectric element 5 is contracted, regardless of when the mover 14 is pushed up by the expansion of the piezoelectric element 5. Since it is selfish, there is a moment when there is a gap between the spacers 31 and 32.

Even at that moment, the arm 8 moves the first leaf spring body 12
Since it is swinging so that the center of rotation is the center of rotation, the other second portion connected to this swinging arm 8
The mover 14 attached to the leaf spring body 13 is easily moved according to the bending deformation of the second leaf spring body 13, and the relative positions of the spacers 31 and 32 are changed. The piezoelectric element 5 has a cantilever shape fixed to the rear end portion 6c of the support frame 6 only at its base end (lower end), and operates the print head, that is, when voltage is applied to the piezoelectric element 5 and stopped. May vibrate repeatedly, and the tip (free end) side of the piezoelectric element 5 may move laterally (vibrate) relative to the lower surface of the mover 14, and as a result, both spacers (contact portions) may be vibrated. ) The relative position of 31, 32 fluctuates.

If the two spacers 31 and 32 are pressed against each other while the relative position is changed, the retracted position of the tip of the arm 8 is changed vertically, and the space between the stoppers 15 and 16 is increased. There is a possibility that a gap is created, and as a result, the amount of advance / retreat of the print wire 7 fluctuates, resulting in variations in the print quality characteristics of the print head.
According to an experiment by the applicant, if the head gap, that is, the distance between the print head and the printing paper is constant, the relative position fluctuation values of the spacers (contact portions) 31 and 32 have individual differences. It was confirmed that it became almost constant regardless of the number of times the piezoelectric element was driven.

An object of the present invention is to solve the above-mentioned conventional technical problems, and it is an object of the present invention to provide a print head device having stable print quality characteristics.

[0012]

In order to achieve the above-mentioned object, a method of assembling a print head device according to the present invention comprises a print mechanism elastically supported on the head body side and having a print wire attached to the tip thereof. In a printing device configured to print by advancing due to the displacement of the piezoelectric element due to the application of voltage, and when the printing mechanism retracts, the base end of the piezoelectric element is fixed to the head body side in a printer configured to contact the stopper on the head body side. , The contact portion to be attached to the free end of the piezoelectric element and the contact portion to be attached to the printing mechanism are arranged so as to face each other and come into contact with each other, and after driving and stopping the piezoelectric element in the printing mechanism, the printing mechanism or the head body The method of fixing the stopper to the side is adopted.

[0013]

EXAMPLES Next, an example in which the present invention is embodied will be described. The basic construction of the print head device is substantially the same as that of FIG. 1 showing a conventional example. That is, reference numeral 1 denotes a head body having a substantially circular shape in a front view, and the cover 2 has a substantially disc-shaped connecting portion 2a.
And a cylindrical portion 2b integrally extending from the outer peripheral edge toward the back surface side of the head body 1, and the head body 1 and the cover 2 are made of an aluminum alloy.

Reference numeral 4 denotes a printing unit, and a plurality of (24 in the embodiment) printing units 4 are radially arranged on the back side of the head body 1. On the front surface of the head body 1, a hollow nose portion 3 in which a predetermined number of guide plates 22 for moving and guiding the print wires 7 in each print unit 4 are installed is provided. The printing unit 4 is mounted on the front end of the piezoelectric element 5 which is formed by adhering piezoelectric ceramics in a laminated shape, and is attached to the front end of the piezoelectric element 5 so as to expand the expansion and contraction movement of the piezoelectric element 5 and transmit it to the printing wire 7. The printing mechanism 9 and the supporting frame 6 that extends rearward from the back surface of the head body 1 for supporting the printing mechanism 9 and the piezoelectric element 5. The support frame 6 is integrally formed in a U-shape by a main strut portion 6a, a sub strut portion 6b, and a rear end portion 6c so as to surround both sides in the longitudinal direction and the rear end portion of the piezoelectric element 5. Note that the auxiliary column portion 6b may be fixed to the rear end portion 6c by brazing.

When charging is performed by applying a voltage, the piezoelectric element 5
Expands in the stacking direction (longitudinal direction) and contracts when discharged, and the piezoelectric element 5 contracts due to a temperature rise. Therefore, the temperature compensator 25 having a positive temperature expansion characteristic for correcting it is supported. It is inserted between the rear end portion 6c of the frame 6 and the rear end of the piezoelectric element 5 and fixed by an adhesive. Printing mechanism 9
Is an arm 8 having a substantially triangular shape in side view formed by brazing the base portion of the printing wire 7 to the tip, and a plate-shaped first leaf spring body 12 extending parallel to the rear side in the longitudinal direction of the main strut portion 6a.
And a plate-shaped second leaf spring body 13 and both spring bodies 1
It is composed of a rigid connecting portion 10 for connecting the ends of the arms 2 and 13, and the connecting portion 10 is fitted and fixed to the base end portion of the arm 8 by brazing or the like. The base end portion of the first leaf spring body 12 is brazed and fixed to the side surface of the main strut portion 6a, while the base end portion of the second leaf spring body 13 contacts the front end face of the piezoelectric element 5 with a spacer 31 as a contact portion. 1 which is in a pressed state via
It is also fixed to the side surface of 4 by brazing or the like.

A spacer 31 as a contact portion joined and fixed to the lower surface of the mover 14 by brazing or the like, and a spacer 32 as a contact portion joined and fixed to the tip (free end) of the piezoelectric element 5 by brazing or the like. Are arranged so as to face each other and abut on a large area. Reference numeral 23 shown in FIG. 3, which is a cross-sectional view taken along the line III-III in FIG. 2, shows a four-bar linkage mechanism that is disposed across the other side of the mover 14 and the sub-column 6b. The four-bar linkage member 23 is made of an elastic material such as a spring plate, and the wide side plate portions 23a, 23a thereof are provided with a notch hole 24 having a substantially H shape in a side view. On the outer diameter side, the left and right wide side plate portions 23a, 23a are fixed to the front and back side surfaces of the auxiliary column portion 6b and the front and back side surfaces of the mover 14 by spot welding (also possible by brazing), and the piezoelectric element 5 applies voltage. 4 link mechanism member 2 when expanding and contracting
The left and right wide side plate portions 23a, 23a in 3 are elastically deformed into a parallelogram shape in a side view so that the mover 14 can move in parallel along the longitudinal direction of the position-fixed sub-post portion 6b. is there. In addition, the left and right wide side plate portions 2
Left and right guide plate portions 23 formed below 3a and 23a
b and 23b are arranged so as to be fixed to the sub strut portion 6b and the main strut portion 6a, while being in contact with the left and right side surfaces of the mover 14 so as to be vertically guided and movable.

As described above, if the movable element 14 is configured to move in parallel along the longitudinal direction of the auxiliary column portion 6b, in other words, to move linearly in the longitudinal direction of the piezoelectric element 5, a laminated layer of piezoelectric ceramics. Bending force does not act on the adhesive surface, and the laminated portion and the adhesive surface are not accidentally peeled off. The assembly order of the printing mechanism 9 according to the present invention is as follows. First, the movable element 14 is joined to the one second leaf spring body 13 which is the Π-type elastic body, and the other first leaf spring body 12 is joined to the main support column 6 a of the support frame 6. Then, the base of the four-bar linkage mechanism member 23 is joined to the sub-column 6b, and the left and right wide-width side plate portions 23a, 23a are sandwiched between the left and right wide-width side plate portions 23a, 23a. The free end side of 23a is joined and fixed. Left and right guide plate portions 23b, 23b
Is fixed to the sub strut portion 6b and the main strut portion 6a.

Next, the base of the piezoelectric element 5 is attached to the support frame 6
The spacer 31 is joined to the rear end portion 6c of the movable element 14, and then the spacer 31 is joined and fixed to the lower surface of the mover 14, and the other spacer 32 is joined and fixed to the free end (upper end surface) of the piezoelectric element 5, and the two spacers 31 are attached. , 32 are assembled so that they face each other and abut. Further, the connecting portion 1 of the pair of leaf spring bodies 12, 13
The base end of the arm 8 is joined to 0.

All the printing units 4 assembled in this way
On the other hand, after applying a voltage to the piezoelectric element 5 under a predetermined condition and accelerating and driving the piezoelectric element on a test basis, the arm 8 is stopped, and in that state, the arm-side stopper 15 and the support-side stopper 1
The arm side stopper 15 and / or the support side stopper 16 are fixed so that the clearance between the arm side stopper 6 and the armature 6 becomes zero.

Here, the predetermined condition is to operate the piezoelectric element 5 in a state in which the gap dimension G (hereinafter referred to as a print gap) between the tip of the print wire 7 in the retracted position and the surface of the platen 30 is set to a predetermined value. If the print gap G is smaller than a certain value, and the arm 8 is stopped after the piezoelectric element 5 is driven, the tip position H of the arm 8 or the tip position H of the print wire 7 attached to the arm 8 in the stationary state. However, the print gap G is higher than when the print gap G is extremely large.

The results of the experiment conducted by the present inventor are shown in FIG. The horizontal axis of FIG. 4 indicates the print gap G (unit: millimeter), and the vertical axis indicates the position H of the tip of the arm 8 or the print state of the arm 8 in a stationary state after driving the piezoelectric element 5 with the values of the print gaps G set above. Tip position H of wire 7 (unit: micrometer,
μm). The experiment was performed on two print wires for one print head device, one is indicated by a white circle and the other is indicated by a black circle.

As can be seen from this figure, when the print gap G is 0.55 mm, even if the print wire 7 is in the most advanced state by driving the piezoelectric element 5, the print wire 7
The leading end of the sheet does not collide with the surface of the platen 30, and the print gap G is the same as infinity. At this time, when the tip position H is set to a reference value (zero) and the print gap G is set to a successively smaller value, the arm 8 is stopped after the piezoelectric element 5 is driven. The position H or the tip position H of the print wire 7 rises. According to the experimental result of the black circles, the leading end position H gradually rises when the printing gap G is 0.55 mm to 0.35 mm.
Is 0.35 mm or less, the tip position H is about ten and several μ.
Stabilize in a raised state. According to the experimental results of Shiramaru,
When the print gap G is 0.25 mm or less, the leading end position H is stabilized in a state of being raised by about 10 μm.

Observing this phenomenon at the position of the black circled printing wire, when the printing gap G is larger than a predetermined value (0.35 mm), the spacer 31 in the mover 14 and the spacer 32 in the piezoelectric element 5 when the arm 8 retracts.
The pressing force for and is insufficient. When the piezoelectric element 5 is driven (expanded and contracted) in this state, the movable element 1 is expanded by the expansion of the piezoelectric element 5.
Regardless of when pushing up 4, the tip of the piezoelectric element 5 separates from the mover 14 when the piezoelectric element 5 contracts, so there is a moment when there is a gap between the spacers 31 and 32.

At that moment, the arm 8 also moves the first leaf spring body 12
Since it is swinging so that the center of rotation is the center of rotation, the other second portion connected to this swinging arm 8
The mover 14 attached to the leaf spring body 13 is easily moved according to the bending deformation of the second leaf spring body 13, and the relative positions of the spacers 31 and 32 are changed. The piezoelectric element 5 has a cantilever shape fixed to the rear end portion 6c of the support frame 6 only at its base end (lower end), and operates the print head, that is, when voltage is applied to the piezoelectric element 5 and stopped. May vibrate repeatedly, and the tip (free end) side of the piezoelectric element 5 may laterally move (vibrate) relative to the lower surface of the mover 14, and as a result, both spacers 3
The relative positions of 1 and 32 change.

Experiments have confirmed that the variation in the relative positions of the spacers 31 and 32 is not affected by the number of times the piezoelectric element is driven. If the spacers 31 and 32 are pressed against each other with the relative position changed, the retracted position of the tip of the arm 8 moves up and down, and a gap is formed between the stoppers 15 and 16. There is a possibility that the print wire 7 moves back and forth, resulting in variations in print quality characteristics of the print head.

On the other hand, when the print gap G is 0.35 mm or less, the spacer 31 on the lower surface of the movable element 14 and the spacer 31 on the upper surface of the piezoelectric element 5 do not separate even when the piezoelectric element 5 contracts, and therefore, the tip of the arm 8 is not formed. The position H does not change before and after driving the piezoelectric element 5, and is considered to be stable. According to the experimental result of the white circle, the printing gap G
The above-mentioned stable state is obtained when is less than 0.25 mm.

In this way, after the piezoelectric element 5 is once driven with the predetermined printing gap set, the supporting side stopper 6b is attached to the auxiliary column 6b so as to abut against the stopper 15 on the arm 8 side in the stationary state. If 16 is fixed, the tip position of the arm 8 in the retracted position (stationary position) is at the most raised position. Therefore, even if the piezoelectric element 5 is driven thereafter, the tip position of the arm 8 in the retracted position (stationary position) will be maintained. No fluctuation occurs, and therefore stable print quality can be obtained.

An embodiment of fixing the stoppers 15 and 16 is shown in FIGS. In this embodiment, the arm-side stopper 15 made of metal, ceramic, synthetic resin, or the like is fixed to the back surface of the arm 8 with an adhesive or the like in advance. On the other hand, the inclined guide surface 17 is formed so that the front end surface of the sub strut portion 6b extends along the longitudinal direction of the arm 8 and approaches the back surface of the arm 8 toward the base end side of the arm 8. The support-side stopper 16 that is fixed after being moved along the inclined guide surface 17 is formed in a wedge shape such as a trapezoid in a side view or a triangle.

An adhesive is applied in advance to the inclined guide surface 17 and / or the contact surface of the support side stopper 16, the support side stopper 16 is moved along the inclined guide surface 17, and the front surface of the support side stopper 16 and the arm. The side stopper 15 is fixed in a state where it is in contact with the back surface of the side stopper 15 (zero clearance). In this case, as shown in (a) or (b) of FIG. 5, a ridge portion 18 is formed on the front end surface of the sub strut portion 6b, and the inclined guide surface 17 is formed on the ridge portion 18, while On the back surface of the support-side stopper 16, the groove portion 1 slidably fitted in the ridge portion 18 is formed.
9 is formed. By doing this, the support-side stopper 1
The work of mounting and moving 6 can be facilitated, and the adhesion area between the support-side stopper 16 and the sub-column portion 6b can be increased.

6 and 7 show the arm-side stopper 15
An embodiment will be shown in which the two are moved relative to the positionally fixed support-side stopper 16 so that they abut each other. Arm 8
An inclined guide surface 20 having a stepped ridge is formed on the back surface so as to approach the support side stopper 16 as it goes to the base end side, while the arm side stopper 15 has a front surface that slides on the inclined guide surface 20. A groove portion 21 that movably fits is formed.

Incidentally, the arm side stopper 15 may be integrally formed on the arm 8 or the support side stopper 16 may be integrally formed on the head main body side such as the auxiliary column portion 6b. Also, the arm side stopper 1 in the arm 8
One or a plurality of through holes are formed in the place where 5 should be provided. Then, the arm 8 is set so that the through hole is located in a cavity (cavity) that is hollowed out in the shape of the arm-side stopper 15 in the molding die, and synthetic resin is injected into the molding die to allow penetration. Since the synthetic resin is hardened in the hole, the mounting strength of the arm-side stopper 15 can be improved.

The pair of leaf spring bodies 12, 13 are
Even if the piezoelectric element 5 corresponding to each printing unit 4 is driven before the base end portion of the arm 8 is joined to the connecting portion 10, the substantially same effect as described above can be obtained. At the time of normal printing operation, as shown in FIG.
When extending in the direction, the connecting portion 10 of both leaf spring bodies 12, 13 swings in the direction of arrow A so that the substantially central portion in the longitudinal direction of the leaf spring body 12 fixed to the main strut portion 6a is the center of rotation. The displacement is performed, the displacement amount is enlarged by the arm 8, and the printing wire 7 is driven so as to project from the nose portion 3. When the charge is rapidly discharged from the piezoelectric element 5, the arm 8 swings in the opposite direction due to the elastic force of the spring bodies 12 and 13, and the arm side stopper 15 abuts the support side stopper 16 and repeats vibration. Attenuates and stops.

[0033]

As described above, according to the present invention, the printing mechanism, which is elastically supported on the head main body side and has the printing wire attached to the tip thereof, is provided by the displacement of the piezoelectric element due to the application of the voltage. In a printing device configured to print by moving forward and contact the stopper on the head body side when the printing mechanism retracts, the base end of the piezoelectric element is fixed to the head body side and attached to the free end of the piezoelectric element. When the piezoelectric element in the printing mechanism is driven in advance and then stopped, the contact portion on the piezoelectric element side and the contact portion on the printing mechanism side are placed in contact with each other. The contact state with the section is stable, and the forward state of the printing wire in the printing mechanism is determined.
If the stopper is fixed to the printing mechanism or the head body side so that the stopper on the head body side contacts the stationary printing mechanism, the stationary state of the printing mechanism stabilizes and the printing quality by operating the piezoelectric element after that The effect of being able to improve.

[Brief description of drawings]

FIG. 1 is a side sectional view of a print head.

FIG. 2 is an enlarged side view of a main part.

3 is a sectional view taken along the line III-III of FIG.

FIG. 4 is a diagram showing a relationship between a print cap and an arm tip position.

5A is an embodiment shown in a sectional view taken along the line VV in FIG. 2, and FIG. 5B is another example shown in a sectional view taken along the line VV in FIG.

FIG. 6 is a side view of an essential part showing another embodiment.

7 is a sectional view taken along the line VII-VII of FIG.

[Explanation of symbols]

 1 Head Main Body 3 Nose Part 5 Piezoelectric Element 6 Support Frame 6b Sub Strut Part 7 Printing Wire 8 Arm 9 Printing Mechanism 12 First Leaf Spring Body 13 Second Leaf Spring Body 14 Mover 15 Arm Side Stopper 16 Support Side Stopper 17, 20 Inclined guide surface 18 Ridge portion 19,21 Groove portion 23 Four-node link mechanism member 30 Platen 31,32 Spacer

Claims (1)

Claim: What is claimed is: 1. A printing mechanism, which is elastically supported on the head body side and has a printing wire attached to the tip thereof, is moved forward by the displacement of the piezoelectric element by the application of a voltage for printing. When the mechanism is retracted, in the printer configured to contact the stopper on the head body side, the base end of the piezoelectric element is fixed to the head body side, and the contact part and the printing mechanism attached to the free end of the piezoelectric element A printing head device characterized in that it is arranged so as to be in contact with a mounting contact portion and abutted, and after driving and stopping the piezoelectric element in the printing mechanism, a stopper is fixed to the printing mechanism or the head body side. How to assemble.