Linear motion mechanism of injection molding machine

A linear motion mechanism for moving an injection unit in the front-rear direction relative to a machine base supporting the injection unit includes: a pair of first linear guides configured to linearly move the injection unit relative to the machine base; and one or more pairs of second linear guides arranged on the rear side relative to the pair of first linear guides, and configured to linearly move the injection unit relative to the machine base.

CROSS-REFERENCE TO RELATED APPLICATION

This application is based upon and claims the benefit of priority from Japanese Patent Application No. 2018-171898 filed on Sep. 13, 2018, the contents of which are incorporated herein by reference.

BACKGROUND OF THE INVENTION

Field of the Invention

The present invention relates to a linear motion mechanism of an injection molding machine.

Description of the Related Art

As disclosed in Japanese Laid-Open Patent Publication No. 09-174606, there have been injection molding machines that include a linear motion mechanism for moving the injection unit in the back and forth direction (for performing linear motion). The linear motion mechanism of an injection molding machine has a linear guide as disclosed in, for example, Japanese Laid-Open Patent Publication No. 09-174606.

SUMMARY OF THE INVENTION

The linear guide of the linear motion mechanism of the injection molding machine needs to be larger as the injection unit becomes larger. However, for example, in the linear guide, longer guide rails tend to be more difficult to manufacture, resulting in poor availability (procurability).

In addition, as shown in Japanese Laid-Open Patent Publication No. 09-174606, it is common in the injection molding machine to support the whole of the injection unit, i.e., from its front part to the rear part, with a single linear guide. However, when the front part and the rear part of the injection unit are supported by a single linear guide, the installation position of the linear guide is subjected to restrictions, depending on the shape or design of the injection unit, for example.

It is therefore an object of the present invention to provide a linear motion mechanism of an injection molding machine which is excellent in the availability (procurability) of the linear guide and in the flexibility of the arrangement of the linear guide.

One aspect of the present invention resides in a linear motion mechanism of an injection molding machine for moving an injection unit in the front-rear direction relative to a machine base supporting the injection unit, including: a pair of first linear guides configured to linearly move the injection unit relative to the machine base; and one or more pairs of second linear guides arranged on the rear side relative to the pair of first linear guides, and configured to linearly move the injection unit relative to the machine base.

According to the present invention, the first linear guide and the second linear guide can be made smaller than conventional linear guides. Thus, it is possible to improve the availability of linear guides.

Also, each of the paired first linear guides and the one or more pairs of second linear guides is a separate component. Therefore, for example, a person skilled in the art may appropriately arrange them according to the configuration of the injection molding machine. This allows flexibility in arrangement or layout of linear guides.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

The linear motion mechanism of an injection molding machine according to the present invention will be detailed below by describing preferred embodiments with reference to the accompanying drawings.

Configuration of First Embodiment

FIG. 1is a side view of a linear motion mechanism10of an injection molding machine of the first embodiment.FIG. 2is a top view of the linear motion mechanism10of an injection molding machine of the first embodiment. The forward and rearward directions referred to herein are indicated by the arrows inFIGS. 1 and 2.

As shown inFIG. 1, an injection molding machine12according to the present embodiment includes a machine base14, an injection unit16on the machine base14and a clamping unit18disposed on the machine base14, on the front side of the injection unit16. The clamping unit18includes a mold20having an injection port. The injection unit16is attached to the machine base14via a linear motion mechanism10. The linear motion mechanism10is a mechanism that moves the injection unit16in the front-rear direction, relative to the machine base14.

The injection unit16is provided with an injection nozzle22. The injection unit16is guided by the linear motion mechanism10so as to move linearly relative to the machine base14, whereby the injection nozzle22is pressed against, or separated from, the injection port of the mold20.

The linear motion mechanism10includes a base portion24supporting the injection unit16from below, and a pair of first linear guides26and a pair of second linear guides28, which each support the injection unit16via the base portion24so that the injection unit can move linearly relative to the machine base14. The paired second linear guides28are arranged more rearward than the paired first linear guides26. Here, in the present embodiment, the positional relationship between the first linear guide26and the second linear guide28is defined by the positional relationship between the front-side end of an aftermentioned guide rail34of the first linear guide26and the front-side end of an aftermentioned guide rail36of the second linear guide28. Therefore, as shown inFIG. 1, the state in which the front-side end, designated at36a, of the guide rail36is located in the rear of the front-side end, designated at34a, of the guide rail34, is defined as a state in which the second linear guide28is arranged more rearward than the first linear guide26.

The base portion24is, for example, a plate-shaped member. The base portion24has a pivot pin30for swiveling or rotating the injection unit16relative to the base portion24, at a position on the center line L of an injection nozzle22in a plan view seen from above. This, for example, makes it easy to finely adjust the direction of the tip of the injection nozzle22in conformity with the shape of a mold20(injection port) used for molding. Further, slide plates32that slide relative to the machine base14are provided on a rear portion of the lower surface of the base portion24. With this configuration, load applied to the first linear guides26and the second linear guides28can be reduced without inhibiting the linear motion of the injection unit16.

The first linear guide26includes the guide rail34that is provided on the machine base14so as to extend in the front-rear direction, and a guide block38provided on the base portion24so as to be movable on the guide rail34in the front-rear direction. Similarly, the second linear guide28includes the guide rail36that is provided on the machine base14so as to extend in the front-rear direction, and a guide block40provided on the base portion24so as to be movable on the guide rail36in the front-rear direction. For example, one or more guide blocks38may be provided for one guide rail34in order to distribute and reduce the load applied to each of the guide blocks38and40. Similarly, one or more guide blocks40may be provided for one guide rail36.

The base portion24, the pivot pin30and the slide plate32may be omitted. For example, the base portion24(and the pivot pin30) may be omitted, and the first linear guide26and the second linear guide28may be adapted to directly support the injection unit16.

As shown inFIG. 2, the paired first linear guides26are disposed symmetrically with respect to the center line L of the injection nozzle22in plan view seen from above, in a state where the center line L of the injection nozzle22is parallel to the front-rear direction, and the paired second linear guides28are disposed in the same manner. Owing thereto, the injection unit16can be stably supported on the machine base14.

As described above, in the present embodiment, the front-side ends36aof the guide rails36of the paired second linear guides28are located more rearward than the front-side ends34aof the guide rails34of the paired first linear guides26. Further, in the present embodiment, the guide rails36of the paired second linear guides28are arranged such that the front-side ends36aare disposed more forward than the rear-side ends34bof the guide rails34of the paired first linear guides26. Therefore, the guide rails36of the paired second linear guides28and the guide rails34of the paired first linear guides26do not reside on the same lines.

In the linear motion mechanism10described above, the first linear guides26support the front portion of the injection unit16while the second linear guides28support the rear portion of the injection unit16. As a result, each of the guide rails34and36can be made shorter in length than the guide rails of the conventional linear guide. Therefore, even if the injection molding machine12is large in size, the first linear guides26and the second linear guide28can be easy to obtain (i.e., the parts availability is improved).

In the above linear motion mechanism10, the arrangement or layout of the linear guides can show good flexibility. For example, when the injection unit16is of a type with the weight concentrated in the vicinity of the injection nozzle22, the load capacity of the guide rails34of the first linear guides26only is enhanced (by, for example, increasing the rail width). Together with this modification, only the first linear guides26may use the guide blocks38of a large type. In addition, for example, the distance between the paired first linear guides26may be narrowed so as to support the injection unit as close to the injection nozzle22as possible. On the other hand, for example, only the second linear guides28may use the guide rails36of a relatively small width. Together with this modification, the second linear guide28may use the guide blocks40of a small type. Also, for example, the distance between the paired second linear guides28can be made greater than that of the paired first linear guides26so as to support the injection unit16stably even when the width of the paired first linear guides26is narrowed.

Further, in the present embodiment, the front-side ends36aof the guide rails36of the paired second linear guides28are located more forward than the rear-side ends34bof the guide rails34of the paired first linear guides26. In this arrangement, the second linear guides28do not need to be extended to the rear end of the injection unit16. Accordingly, the machine base14does not need to be extended to the rear end of the injection unit16either, which is advantageous in making the machine base14compact (shortening the overall length of the machine base14), and hence it is also advantageous for downsizing of the injection molding machine12.

Additionally, in the present embodiment, the first linear guides26and the second linear guides28are configured to support the injection unit16via the base portion24. This configuration can make it easy to change the injection unit16, that is, the injection unit16can be changed merely by replacing the injection unit16on the base portion24with another unit.

Though the first embodiment has been described as one example of the present invention, it goes without saying that various modifications and improvements can be added to the above first embodiment. It is apparent from the scope of the claims that modes added with such modifications and improvements should be incorporated in the technical scope of the invention.

FIG. 3is a top view of a linear motion mechanism10of an injection molding machine of Modification 1.

For example, as shown inFIG. 3, the front-side ends36aof the guide rails36of the paired second linear guides28are located more rearward than the rear-side ends34bof the guide rails34of the paired first linear guides26. Thus, the linear motion mechanism10according to the present invention offers good flexibility in arranging the linear guides.

FIG. 4is a top view of a linear motion mechanism10of an injection molding machine of Modification 2.

In the first embodiment, an example has been described in which the guide rails36of the paired second linear guides28are not aligned with the guide rails34of the paired first linear guides26. Yet, for example, the guide rails34of the paired first linear guides26and the guide rails36of the paired second linear guides28may be aligned with each other, as shown inFIG. 4. Thus, the linear motion mechanism10according to the present invention offers good flexibility in arranging the linear guides.

FIG. 5is a top view of a linear motion mechanism10of an injection molding machine of Modification 3.

One or more pairs of second linear guides28may be provided. For example, the paired second linear guides28(seeFIG. 2) described in the first embodiment and the paired second linear guides28(seeFIG. 3) described in Modification 1 are arranged in different manners. By combining these arrangements, as shown inFIG. 5, multiple pairs of second linear guides28may be provided. Thus, the linear motion mechanism10according to the present invention offers good flexibility in arranging the linear guides.

FIG. 6is a top view of a linear motion mechanism10of an injection molding machine of Modification 4.

For example, the method of arrangement or layout differs between the paired second linear guides28(seeFIG. 3) described in Modification 1 and the paired second linear guides28(seeFIG. 4) described in Modification 2. These arrangements may be combined to provide multiple pairs of second linear guides28, as shown inFIG. 6. Thus, the linear motion mechanism10according to the present invention offers good flexibility in arranging the linear guides.

Invention Obtained from the Embodiment

The invention which can be grasped from the above-mentioned embodiment and Modifications is described below.

The linear motion mechanism (10) of an injection molding machine (12) for moving an injection unit (16) in the front-rear direction relative to a machine base (14) supporting the injection unit (16) includes: a pair of first linear guides (26) configured to linearly move the injection unit (16) relative to the machine base (14); and one or more pairs of second linear guides (28) arranged on the rear side relative to the pair of first linear guides (26), and configured to linearly move the injection unit (16) relative to the machine base (14).

The first linear guide (26) and the second linear guide (28) may be smaller than conventional linear guides. Therefore, this configuration offers good availability (procurability) and good flexibility in arrangement.

The pair of first linear guides (26) and the pair of second linear guides (28) may be arranged in parallel with the front-rear direction, and each pair may be disposed symmetrically with respect to the center line (L) of an injection nozzle (22) of the injection unit (16) in plan view, in a state where the center line (L) is parallel to the front-rear direction. With this configuration, the injection unit (16) can be stably supported on the machine base (14).

The linear motion mechanism (10) may further include a base portion (24) configured to support the injection unit (16), and the first linear guides (26) and the second linear guides (28) may be configured to support the injection unit (16) via the base portion (24) so as to be linearly movable. Thus, for example, this configuration can make it easy to change the injection unit (16), that is, the injection unit (16) can be changed merely by replacing the injection unit (16) on the base portion (24) with another unit.

The base portion (24) may be provided with a pivot pin (30) configured to rotate the injection unit (16) with respect to the base portion (24). This, for example, makes it easy to finely adjust the direction of the tip of the injection nozzle (22) in conformity with the shape of the mold (20) used for molding.

The pivot pin (30) may be located on the center line (L) of the injection nozzle (22) of the injection unit (16) in plan view. This, for example, makes it easy to finely adjust the direction of the tip of the injection nozzle (22) in conformity with the shape of the mold (20) used for molding.

The base portion (24) may be provided with a slide plate (32) configured to slide relative to the machine base (14). This, for example, makes it possible to reduce the load applied to the first linear guides (26) and the second linear guides (28) without inhibiting the linear motion of the injection unit (16).

Each of the first linear guides (26) and the second linear guides (28) may include a guide rail (34,36) extending in the front-rear direction and a guide block (38,40) movable along the front-rear direction on the guide rail (34,36). The length of each of the guide rails (34) of the first linear guides (26) and the guide rails (36) of the second linear guides (28) can be made shorter than the guide rails of the conventional linear guide. Therefore, even if the injection molding machine (12) is large in size, this configuration offers good availability of the first linear guides (26) and the second linear guides (28). Also, for example, it is easy to make the distance between the paired first linear guides (26) and the distance between the paired second linear guides (28) different, as appropriate. Thus, the linear guides (26,28) of the linear motion mechanism (10) according to the present invention offer good flexibility in arrangement or layout.

The front-side ends (36a) of the guide rails (36) of at least one pair of the second linear guides (28) may be located more rearward than the rear-side ends (34b) of the guide rails (34) of the first linear guides (26). Thus, the linear guides (26,28) of the linear motion mechanism (10) according to the present invention offer good flexibility in arrangement.

The front-side ends (36a) of the guide rails (36) of at least one pair of the second linear guides (28) may be located more forward than the rear-side ends (34b) of the guide rails (34) of the first linear guides (26). Thus, the linear guides (26,28) of the linear motion mechanism (10) according to the present invention offer good flexibility in arrangement. Further, in this arrangement, the second linear guides (28) do not need to be extended to the rear end of the injection unit (16). Accordingly, the machine base (14) does not need to be extended to the rear end of the injection unit (16) either, which is advantageous in making the machine base (14) compact, and hence it is also advantageous for downsizing of the injection molding machine (12).

The guide rails (36) of at least one pair of the second linear guides (28) may be arranged so as not to be aligned with the guide rails (34) of the first linear guides (26). Thus, the linear guides (26,28) of the linear motion mechanism (10) according to the present invention offer good flexibility in arrangement.

The present invention is not particularly limited to the embodiment described above, and various modifications are possible without departing from the essence and gist of the present invention.