ES2552104A1 - Guide for printer print head support slider, procedure for obtaining a printer guide and installation for obtaining this guide (Machine-translation by Google Translate, not legally binding) - Google Patents

Abstract

Guide for printer printhead support slider, procedure for obtaining a printer guide and installation for obtaining this guide. Guide (1) for slide (2) of printer print head support (4), the guide (1) being an elongated bar whose surface is designed to slide the slide (2), the bar (1) being treated superficially so that it has a certain maximum roughness (Δ tM), which comprises a coating of hydrogenated amorphous carbon (3) on its surface, the thickness being (tor) of the coating (3) above the maximum roughness (Δ tM). The invention also relates to a method for obtaining the guide and to an installation for manufacturing the guide. (Machine-translation by Google Translate, not legally binding)

Description

GUIDE FOR PRINTER PRINT HEAD SUPPORT SLIDE, PROCEDURE FOR OBTAINING A PRINTER GUIDE AND INSTALLATION FOR OBTAINING THIS GUIDE

Field of the Invention

The present invention belongs to the sector of the sliding guide assemblies for printers, which are subject to high duty cycles, and in which it is crucial to achieve a useful life in good sliding conditions to have a friction coefficient as small as possible and with minimum lubricant needs.

Background of the invention

15 Guides for slides of printer printhead holders are known, which are elongated bars whose surface is intended to slide the slide, the bar being surface treated, generally ground and polished, so that entry is guaranteed a translation movement under conditions of minimum friction.

20 These sliding-guide assemblies have high wear resistance requirements, since a life as long as possible with minimal wear is sought, as this ends up reducing the print quality.

For this, it is known to have a sintered copper slide, combined with a lubricant that can circulate through the porosities of the sintered material and a sufficient degree of grinding and polishing to guarantee a slip with a minimum friction for a predetermined number of cycles.

These assemblies, which require the use of a lubricant, operate in environments with the presence of vapors and

micro-drops of chemical products, among which steam and micro-drops of ink stand out. Therefore, it is

It is inevitable that a paste will be produced as a result of the combination of the steam and the microdrops of ink,

30 among others, and the lubricant. This paste is not easy to remove, it can solidify and inevitably ends up negatively affecting the life of the set, and the precision with which it works.

Obvious solutions are to improve grinding and polishing, have better lubricants and avoid the presence of vapors and microdroplets of chemicals. But from a certain point, optimize these

35 aspects become very expensive, and there will always be a formation of a certain amount of the aforementioned paste that can form solid precipitates and encrustations.

Therefore, the inventors consider that there is a need to solve these shortcomings.

Description of the invention

To solve these shortcomings, the present invention proposes a guide for sliding head support

printer printing, the guide being an elongated bar whose surface is intended to slide the

sliding, the bar being treated superficially so that it has a certain maximum roughness

45 LIt "" characterized by the fact that it comprises a hydrogenated amorphous carbon coating on its surface, which combines C-C and C-H bonds with Sp2 and Sp3 hybridizations, the thickness of the coating being greater than the maximum roughness LIt ".

The inventors have been able to verify that this coating allows to reach friction coefficients even

50 less than 0.1, and this without the need to apply any lubricant. Therefore, paste production associated with the simultaneous presence of ink and lubricant is avoided or minimized, thereby:

The necessary use of lubricants is avoided, that is to say, that you can work dry; The useful life of the set is extended;

55 The behavior of the whole is improved, the movement being more precise;

In the present description it is important to distinguish between the maximum roughness LItM and the average roughness LItRMS.

What is claimed is that the thickness of the coating is greater than the maximum roughness, as this is the

corresponding to the maximum roughness peaks, which are those that have to be covered by

60 coating to achieve maximum wear resistance. The inventors have been able to determine that these peaks are responsible for the rapid wear of the slide.

This maximum roughness can be determined according to each material by scanning with interferential optical microscopy or with confocal microscopy. The three-dimensional image, calculated from the tomographs 65 obtained from the surface of the material allows to determine the maximum value of the roughness, LIt ", and the roughness

average LltRl.ls. An example of this technique is the SENSOFAR system and the advanced analysis software SensoMAP (http: //'MVW.sensofar.com/sensofar).

By surface treatment, any surface treatment is intended to confer a certain roughness to the guide, such as grinding and / or polishing. For guidance and approximate purposes, the following table shows orders of magnitude of average typical roughness according to the different types of treatment:

Treatment

Ru ossity half-hearted

Laser cutting Esmeri side Milling Resistance ion Shot blasting Grinding Polishing Grinding Super finishing

32 0.4 3.2 1.6 0.6 0.2 0.2 to 0.4 0.2 to 1.6 0.05 to 0.2

10 Advantageously, the thickness of the coating is greater than the maximum roughness in at least a five-to-one ratio, so that there is a margin of safety against the indeterminacy that the results of the maximum roughness measurement can have. However, the person skilled in the art, depending on the desired life of the guide in minimum friction conditions, can adapt this relationship.

Advantageously, the guide comprises an activation surface treatment and a foundation or adhesion layer of chromium, nickel, tungsten, titanium or combinations thereof such as titanium chromium, or the carbides and metal nitrides corresponding to these metals such as carbide of tungsten or titanium nitride or combinations thereof, between the surface of the bar and the coating.

The invention also relates to a method of obtaining a printer guide intended to be subjected to a normal force (FN) applied by the slider for at least a predetermined number of cycles (N), comprising the steps of:

to. Apply a surface treatment to a steel bar, so that it has a certain roughness (, 1t. ~ F);

b.

Determine the thickness of a coating (to) from the noonal force (FN) and work cycles

(N) that it must withstand before reaching maximum wear (w);

C.

Cover the guide by physical vapor deposition with an amorphous carbon coating

hydrogenated (3) with the thickness of the coating (to) determined. 30

Preferably, step b) of determining the thickness of the coating (to) is carried out by the following formula:

35 to = k · w · FN · N / a + Lltl.l

where:

wes maximum wear;

40 FN is the normal force applied by the slide on the glutton; N is the minimum number of cycles that the guide must withstand before reaching maximum wear (w); a is the width according to the circular direction (at the edge of the cross section) of the contact area between the slide and the guide; k is a factor that is worth 2 if the duty cycle is reciprocating or 1 if the cycle is reciprocating;

45 The reciprocating cycle occurs when there is only a relative translation between the two elements. A cycle without swaying is the one that occurs when for example the relative path is closed, for example circular, that is to say that in each cycle the slider passes only once for each point of the guide.

The invention also relates to an installation for obtaining a glutton according to any of the described variants of the invention, comprising:

A sputtering chamber containing argon for the application of a surface activation treatment and a foundation or adhesion layer;

55 A plasma-assisted vapor phase chemical deposition chamber containing a precursor vapor

65 P201 530555

carbon, for example methane; and a set of degassing sluice and consecutive plasma activation sluice, each provided with a sealed cylindrical opening for the passage of the guide and arranged coaxially with the openings of the cathode spray and chemical deposition chambers, the locks being of degassing and activation of argon-filled plasma and each connected to a vacuum pump, so that a guide degassing can be applied consecutively to the guide, an activation of the guide surface by plasma, a foundation layer or of adhesion on the surface of the guide and a coating on the layer of adhesion.

According to various advantageous features of the installation, which can be combined whenever possible:

-

the cameras are adjacent and are coupled;

-

The chambers are separated by a wall provided with a sealed cylindrical opening for the passage of the guide, the two chambers being provided on their walls opposite to the separation wall of two sealed openings for the entrance and exit of the guide.

-

the installation comprises, in the transition between the degassing lock and the plasma activation lock and between the plasma activation lock and the cathode spray chamber two connections to a vacuum pump.

-

The installation comprises at the entrance an inlet bushing provided with two consecutive Teflon bearings (PTFE), the area between the bearings being provided with a connection to a vacuum pump.

-

The installation comprises means for supplying heat to the degassing chamber.

Finally, the opening between the cathode spray and chemical deposition chambers has a connection to a vacuum pump.

Brief description of the figures

To complement the description and in order to help a better understanding of the characteristics of the invention, according to an example of practical realization thereof, a set of figures is accompanied as an integral part of the description in which Illustrative and non-limiting, the following has been represented:

Figure 1 shows the relationship between coating thickness and maximum roughness.

Figure 2 schematically shows a guide-sliding assembly.

Figure 3 shows the parameters to be taken into account in a calculation of wear in the case of a slide that is moved by a cylindrical guide.

Figure 4 shows an installation for coating the guide according to the invention.

Figure 5 shows a detail of the guide.

Figure 6 shows a sliding sleeve provided with three shoes coated with hydrogenated amorphous carbon.

Figure 7 is a three-dimensional topography of the 20x magnification, unwanted area of the sliding axis. The roughness measured in the sliding direction is Rax = 777nm. It is a rectified surface.

Figure 8 is a three-dimensional topography of the 20x magnification, area with wear on the sliding axis. The roughness measured in the sliding direction is Rax = 126nm, while the roughness in the transverse direction is Ray = 1225nm. It is a rectified surface.

Description of an embodiment of the invention

As can be seen in Figures 1 and 2, the present invention relates to a guide 1 for slide 2 of printer print head support 4, the guide 1 being an elongated bar whose surface is intended to slide the slide 2 , the bar 1 being ground and polished so that it has a certain maximum roughness LltM, characterized by the fact that it comprises a carbon coating

hydrogenated amorphous 3 on its surface, the thickness of the coating 3 being greater than the maximum roughness

¿Lt /, /.

In Figures 7 and 8, whose position coordinates are indicated in microns, and where the height of the enveloping parallelepiped is one micron (resulting in an enlarged graph according to the Z direction), a topography showing the resulting roughness peaks can be seen of a grinding. From this determination, a coating thickness can be determined, which should be greater than the height of the major peaks.

The invention also refers to a method of obtaining a printer 1 of the shape 4 intended to be subjected to a normal force FN applied by the slide 2 during the mills a predetermined number of cycles N, comprising the steps of:

to.

Grind and polish a steel bar 1, so that it has a certain roughness ¿l1 /, /;

b.

Determine the thickness of a coating Ir¡ from the normal force FN and the duty cycles N that it must withstand before reaching maximum wear w;

C.

Cover the guide by physical vapor deposition with a hydrogenated amorphous carbon coating 3 with the thickness of the coating determined.

Stage b for determining the thickness of the coating is carried out using the following formula:

10 = k 'w'FN' N / a + Llt /, /

where:

wes maximum wear; FN is the normal force applied by the slide 2 on the guide 3; N is the minimum number of cycles that the guide must withstand before reaching maximum wear w; a is the width according to the circular direction of the contact zone between the slide 2 and the figure 1; k is a factor that is worth 2 if the duty cycle is reciprocating or 1 if the cycle is reciprocating; Lt /, / is the maximum roughness.

As is known, wear can be expressed as:

w = Volume Shifted / (FN. OrJ

Where the volume displaced is the material displaced during wear. FN is the normal force applied. Pray the total displacement. In the case of a reciprocating movement, it will be worth N * d, where N is the number of cycles and d the path length of each cycle. Now, if the cycle is reciprocating, in each cycle the slide It passes twice through the same points, producing twice as much wear, hence the introduction of a factor 2, that is to say that in case of reciprocating:

In general, according to the number of passes k, the total displacement value will be:

As can be seen in Figures 4 and 5, the invention also relates to an installation 5 for the obtaining a guide 1 according to any of the variants of the guide according to the invention, comprising:

A cathode spray chamber 6 containing argon for foundation application or adherence; A plasma-assisted vapor deposition chamber 7 containing a vapor carbon precursor, such as methane; Being the adjacent cameras and being coupled;

Characterized by the fact that the chambers are adjacent and are separated by a wall 18 provided with a sealed cylindrical opening 18 'for the passage of the guide 1, the two chambers being provided on their walls opposite to the path separation wall 18 watertight openings for the entry and exit of the guide 1.

The installation comprises a set of degassing sluice 9 and a consecutive plasma activation sluice 10, each provided with a sealed cylindrical opening for the passage of the guide 1 and arranged coaxially with the openings of the cathode spray chambers 6 and of chemical deposition 7, the degassing locks 9 and plasma activation 10s being filled with argon and each connected to a vacuum pump 13, 14, so that a degassing of the guide can be applied consecutively to the guide, an activation of Plasma of the guide surface. a foundation or adhesion layer on the surface of the guide and a coating layer 3 on the adhesion layer.

The installation comprises, in the transition between the degassing lock 9 and the activation lock of

plasma 10 and between the plasma activation lock 10 and the cathode spray chamber 6 paths

connections 15, 16 to a vacuum pump.

10 The installation comprises at the entrance an inlet bushing 21 provided with two consecutive PTFE bearings 20, the area between the bearings being provided with a connection 19 to a vacuum pump.

The installation also includes heat supply means 22 to the degassing chamber 9.

15 The opening 18 'between the sputtering and chemical deposition chambers 6 has a connection 17 to a vacuum pump.

In the present application a guide for sliding has been claimed. However, it would also be possible to give

20 a solution to the drawbacks of the prior art, which would constitute another invention, with a slide as described in the following points, and which has been illustrated in Figure 6:

Slider C for printer glutton, which has a body with an e-shaped section, so that it can be attached to the guide without interfering with the supports thereof, the bottom face of the slide being provided with a

25 or more friction surfaces, characterized by the fact that the friction surface (s) are rectified so that they have a certain maximum roughness, and comprise a hydrogenated amorphous carbon coating whose thickness is at least greater than said maximum roughness.

Preferably, the coating is five times the roughness.

Preferably, the carbon is in the hydrogenated amorphous carbon form.

Advantageously, the hydrogenated amorphous carbooo coating is deposited by means of the physical deposition technique in the vapor phase or by chemical vapor deposition assisted by plasma.

Very advantageously, the slide comprises friction surfaces or shoes, the body being provided with insertion grooves in its lower face, one side of the shoes having a section complementary to that of the grooves, the side being provided with one side of one of Measuring surfaces

40 Preferably, the insertion side in the shoe grooves has a trapezoidal section, and the groove section is a dovetail.

In this text, the word ~ understands · and its variants as · understanding ", etc., should not be construed as excluding, that is, they do not exclude the possibility that what has been described includes other elements, steps, etc.

On the other hand, the invention is not limited to the specific embodiments that have been described but also encompasses, for example, the variants that can be made by the average person skilled in the art, within what follows from the claims.

Claims (8)

1.-Guide (1) for slide (2) of printer print head support (4), the glutton (1) being a bar 5 elongated by whose surface the slide (2) is intended to slide, the bar (1) being superficially treated so that it has a certain maximum roughness (LltM), characterized by the fact that it comprises a hydrogenated amorphous carbon coating (3 ) on its surface, the thickness (to) of the coating (3) being greater than the maximum roughness (LltM). 2. A guide according to claim 1, comprising a surface treatment of activation and a foundation or adhesion layer of chromium, nickel, tungsten, titanium or combinations thereof such as titanium chromium, or the carbides and metal nitrides corresponding to these metals such as tungsten carbide or titanium nitride or combinations thereof, between the surface of the bar and the coating (3). 15 3.-Procedure for obtaining a printer guide (1) (4) intended to be subjected to a normal force (F, ..) applied by the slide (2) for at least a predetermined number of cycles (N) , which includes the stages of: to. Apply a surface treatment to a steel bar (1), so that it has a certain roughness (LltM);

b.

Determine the thickness of a coating (to) from the normal force (F, ..) and the duty cycles

(N) that it must withstand before reaching maximum wear (w);

C.

Cover the guide by physical vapor deposition or by chemical deposition in phase

steam with a hydrogenated amorphous carbon coating (3) with the thickness of the coating (to) determined in step b. 4. Method according to claim 3, wherein step b) of determining the thickness of the coating (to) is carried out by the following formula: to = k 'w'F "" N / a + LltM where: 35 W is the maximum wear; FN is the normal force applied by the slide (2) on the glutton (3); N is the minimum number of cycles that the guide must withstand before reaching maximum wear (w); a is the width according to the circular (transverse) direction of the contact area between the slide (2) and the glutton (1); k is a factor that is worth 2 if the work cycle is of va ivén or 1 if the cycle is without sway; 5. Installation (5) for obtaining a guide (1) according to any of claims 1 to 3, characterized in that it comprises: A cathode spray chamber (6) containing argon for the application of a surface treatment of foundation or adhesion; A plasma-assisted vapor deposition chamber (7) containing methane; and a set of degassing lock (9) and consecutive plasma activation lock (10), each provided with a sealed rich cylinder opening for the passage of the guide (1) and arranged 50 coaxially with the openings of the cathode spray (6) and chemical deposition chambers (7), the degassing (9) and plasma activation locks (10) being filled with argon and each connected to a vacuum pump (13,14), so that a degassing of the glutton, a plasma activation of the glutton surface, a foundation or adhesion layer on the guide surface and a coating layer can be applied consecutively to the glutton (3) about the 55 adhesion layer. 6. Installation according to claim 5, wherein the cameras are adjacent and are coupled. 7. Installation according to claim 6, wherein the chambers are separated by a wall (18) provided with 60 a sealed cylindrical opening (18 ') for the passage of the guide (1), the two chambers being provided on their walls opposite to the separation wall (18) of two sealed openings for the entry and exit of the guide ( one). 8. Installation according to claim 5, comprising, in the transition between the degassing lock (9) and the plasma aclivation lock (10) and link the plasma aclivation lock (10) and the cathode spray chamber (6) two connections (15, 16) to a vacuum pump. 9. Installation according to any of claims 5 to 8, comprising at the entrance a bushing of 5 inlet (21) provided with two consecutive teflon bearings (PTFE) (20), the area between the bearings being provided with a connection (19) to a vacuum pump. 10. Installation according to claim 5 and any that depends on it, which comprises means for supplying heat (22) to the degassing chamber (9). 11. Installation according to any of claims 5 to 10, wherein the opening (18 ') between the cathode spray (6) and chemical deposition chambers (7) has a connection (17) to a vacuum pump .