JP4486613B2 - Drive mechanism of injection molding machine - Google Patents

Description

  The present invention relates to a drive mechanism of an injection molding machine including an injection block to which a linear motion is transmitted and a screw coupling to which a rotational motion is transmitted via a timing belt.

  Conventionally, an injection block to which axial movement is transmitted from an advancing / retreating drive unit and a screw coupling to which rotational motion is transmitted via a timing belt of the rotation drive unit are provided, and a bearing portion is provided by an inner peripheral portion of the injection block. As a drive mechanism for an injection molding machine that rotatably supports a screw coupling via the injection molding machine, a drive mechanism for an injection molding machine disclosed in Japanese Patent Publication No. 5-50973 already proposed by the present applicant is known. .

FIG. 9 shows an outline of a drive mechanism 60 having the same basic structure as the drive mechanism disclosed in the publication. The drive mechanism 60 rotatably supports a screw coupling 62 to which rotational motion is transmitted by an injection block (guide joint) 61 to which linear motion is transmitted, and between the injection block 61 and the screw coupling 62, The load cell 63 includes a washer-shaped load cell 63 that has an inner ring portion 63i, an outer ring portion 63o, and an intermediate strain portion 63m, and detects axial pressure applied to the screw coupling 62. Inner ring portion 63i and a pair of bearing portions disposed on both sides of the inner ring portion 63i, that is, a thrust bearing 64 disposed on the front end surface side of the inner ring portion 63i and an angular surface disposed on the rear end surface side of the inner ring portion 63i. The ball bearing 65 is fixed on the outer periphery of the screw coupling 62 by a bearing nut 66, and the outer ring portion 63o of the load cell 63 is injected into the injection block. Those fixed to the click 61. In this case, linear movement is transmitted to the injection block 61 from an unillustrated screw advance / retreat drive motor (servo motor) and an advance / retreat drive unit 67 having a ball screw mechanism, and to the screw coupling 62, screw rotation. Rotation drive having a drive motor (servo motor) 69, a drive pulley 70 attached to the drive motor 69, a driven pulley 71 attached to the screw coupling 62, and a timing belt 72 bridged between the drive pulley 70 and the driven pulley 71 A rotational motion is transmitted from the portion 68. As a result, the pressure detection is not affected by both the preload due to the tightening of the bearing nut 66 and the injection block 61, so that the detection accuracy and reliability can be improved, and the high accuracy management for the preload and the injection block 61, injection can be performed. Since high-precision processing and assembly of the base, injection drive base, guide shaft, and the like are not required, parts manufacture and mechanism assembly are facilitated.
JP 5-50973

  However, the conventional drive mechanism of the injection molding machine described above has the following problems to be solved.

  First, when the timing belt 72 is used for the rotation drive unit 68, the screw coupling 62 supported by the injection block 61 that moves straight is pulled in one radial direction by the rotation drive unit 68. The screw itself attached to is also subjected to a tensile load in the radial direction. Therefore, so-called galling occurs on the heating cylinder due to misalignment of the screw due to long-term use, which not only hinders smooth operation but also reduces durability due to wear.

  Second, when the screw coupling 62 is pulled in one radial direction by the rotation driving unit 68, the angular ball bearing 65 also receives a tensile load in the radial direction. In addition, the angular ball bearing 65 repeatedly receives a pressure force applied backward from the screw coupling 62 in this state, and usually an inevitable clearance on the mechanism exists between the injection block 61 and the screw coupling 62. Therefore, the angular ball bearing 65 also causes galling or increases the frictional resistance against the injection block 61 in the axial direction, leading to a decrease in detection accuracy of the load cell 63 that directly contacts the angular ball bearing 65. Although the influence of the tensile load in the radial direction (tilting of the angular ball bearing 56) can be reduced by tightening the bearing nut 66 more strongly, the strong tightening adversely affects the detection characteristics of the load cell 63, and the bearing nut 66 It cannot be handled by tightening.

  An object of the present invention is to provide a drive mechanism of an injection molding machine that solves the problems existing in the background art.

  In order to solve the above-described problems, the present invention is a screw cup in which a rotational motion is transmitted via an injection block 3 to which a linear motion in the axial direction Fa is transmitted from the forward / backward drive unit 2 and a timing belt 5 of the rotational drive unit 4 When the drive mechanism 1 of the injection molding machine M having the ring 6 and rotatably supporting the screw coupling 6 via the bearing portion 7 by the inner peripheral portion of the injection block 3 is used, It is provided with a pressing adjusting means P having a position adjusting portion Pm that can adjust the pressing position Xp while pressing the screw coupling 6 in the opposite direction to the tensile load Fp by the timing belt 5. .

  In this case, according to a preferred aspect of the invention, the pressure adjusting means P has a tap hole 11n and is screwed into the base hole part 11 attached to the injection block 3 and the tap hole 11n, and the tip part is a screw coupling 6. Can be configured using an adjustment pressing bolt 12 that can be pressed directly or indirectly. On the other hand, the drive mechanism 1 can incorporate a load cell 8 that detects the pressure in the axial direction Fa between the injection block 3 and the screw coupling 6. At this time, a thrust bearing 13 is interposed between the screw coupling 6 and the front end face 8f of the load cell 8, and an angular ball bearing 14 in which the bearing portion 7 is disposed on the rear end face 8r side of the load cell 8 and the angular ball bearing 14 are provided. More specifically, the load cell 8 is configured in a washer shape having an inner ring portion 8i, an outer ring portion 8o, and an intermediate strain portion 8m, and the thrust bearing 13, The ring portion 8 i, the angular ball bearing 14, and the second bearing 15 can be fixed on the outer peripheral portion of the screw coupling 6 by the bearing nut 16, and the outer ring portion 8 o can be fixed to the injection block 3. As the second bearing 15, a cylindrical roller bearing 15x or a deep groove ball bearing 15y can be used.

  According to the drive mechanism 1 of the injection molding machine M according to the present invention having such a configuration, the following remarkable effects can be obtained.

  (1) Since the pressure adjusting means P that directly or indirectly presses the screw coupling 6 in the opposite direction to the tensile load Fp by the timing belt 5 is provided, the screw can be obtained by using the timing belt 5 for the rotation drive unit 4. Even if the radial tension load Fp is applied to the coupling 6, screw misalignment can be effectively prevented. Therefore, it is possible to avoid the occurrence of screw galling with respect to the heating cylinder, and it is possible to improve durability by ensuring smooth operation and reducing wear.

  (2) According to a preferred embodiment, the pressure adjusting means P is screwed into the base 11 having the tap hole 11n and attached to the injection block 3, and the tap hole 11n, and the tip directly connects the screw coupling 6 If it comprises using the adjustment press volt | bolt 12 which can be pressed manually or indirectly, it can implement easily and at low cost by a small number of parts. In addition, it can be easily carried out by retrofitting or simple improvement to an existing injection molding machine.

  (3) The load cell 8 for detecting the pressure in the axial direction Fa between the injection block 3 and the screw coupling 6 is built in according to a preferred mode, and the thrust bearing 13 is interposed between the screw coupling 6 and the front end face 8 f of the load cell 8. In addition, if the bearing portion 7 is constituted by the angular ball bearing 14 arranged on the rear end face 8r side of the load cell 8 and the second bearing 15 arranged side by side on the angular ball bearing 14, the first side arranged side by side on the angular ball bearing 14 is arranged. Since the radial load is received by the two bearings 15, it is possible to avoid the occurrence of galling due to the angular ball bearing 14 that directly contacts the load cell 8 and the problem that the frictional resistance against the injection block 3 in the axial direction is increased. Detection accuracy can be increased.

  (4) According to a preferred embodiment, the load cell 8 is configured in a washer shape having an inner ring portion 8i, an outer ring portion 8o, and an intermediate strain portion 8m, and the thrust bearing 13, the inner ring portion 8i, the angular ball bearing 14 and the first If the two bearings 15 are fixed on the outer peripheral portion of the screw coupling 6 by the bearing nut 16 and the outer ring portion 8o is fixed to the injection block 3, the preload and the injection block by tightening the bearing nut 16 are secured. 3 Improvement of detection accuracy and reliability by eliminating the influence of both, as well as high-precision management for preload and high-precision processing and assembly of the injection block 3 etc. are not required for parts manufacturing and mechanism assembly This can contribute to facilitation.

  Next, the best embodiment according to the present invention will be given and described in detail with reference to the drawings.

  First, the structure of the injection molding machine M provided with the drive mechanism 1 according to the present embodiment will be described with reference to FIGS. 1 and 2.

  In FIG. 2, M is an injection molding machine, and particularly shows an injection device Mi. The injection device Mi includes an injection table 21 and an injection driving table 22 disposed behind the injection table 21, and a plurality (two in the illustrated example) of guide shafts 23 are installed between the injection table 21 and the injection driving table 22. Further, the injection block 3 is slidably loaded on the guide shafts 23 through the guide bush portions 24. On the other hand, the injection drive base 22 supports the transmission shaft 25 so as to be rotatable. A driven pulley 26 is attached to the rear end of the transmission shaft 25, and rotation is transmitted to the driven pulley 26 from a screw advance / retreat drive motor (servo motor) (not shown). The rear end of the ball screw 27 s of the ball screw mechanism 27 is coupled to the front end of the transmission shaft 25, and the ball nut 27 n that is screwed into the ball screw 27 s is coupled to the rear end of the injection block 3. Therefore, the screw advance / retreat drive motor (not shown) and the ball screw mechanism 27 constitute the advance / retreat drive unit 2. As a result, a linear movement for injection is transmitted from the advance / retreat drive unit 2 to the injection block 3.

  On the other hand, a rear end of the heating cylinder 28 is attached to the injection table 21, and a screw 29 is inserted through the heating cylinder 28. Further, the screw coupling 6 is rotatably supported by the inner peripheral portion of the support hole 3 s provided in the injection block 3 via the bearing portion 7, and the rear end of the screw 29 is placed at the center position of the front end of the screw coupling 6. Support it together. Further, a screw rotation drive motor (servo motor) 31 is supported by a support 30 attached to the outer surface of the injection block 3, and the drive motor 31 and the screw coupling 6 are connected via a rotation transmission mechanism 32. The rotation transmission mechanism 32 spans between a drive pulley 33 attached to the drive shaft of the drive motor 31, a driven pulley 34 attached with the shaft center aligned with the front end of the screw coupling 6, and between the drive pulley 33 and the driven pulley 34. A timing belt 5 is provided. The drive motor 31 and the rotation transmission mechanism 32 constitute the rotation drive unit 4. As a result, the rotational movement for measurement is transmitted to the screw coupling 6 from the rotational drive unit 4.

  Next, the structure of the principal part of the drive mechanism 1 according to the present embodiment will be described with reference to FIGS.

  The drive mechanism 1 includes the injection block 3 to which the linear movement in the axial direction Fa is transmitted from the advance / retreat drive unit 2 and the screw coupling 6 to which the rotational motion is transmitted via the timing belt 5 of the rotation drive unit 4. The screw coupling 6 is configured to be rotatably supported on the inner peripheral portion of the injection block 3 via the bearing portion 7. The drive mechanism 1 incorporates a load cell 8 that detects the pressure in the axial direction Fa between the injection block 3 and the screw coupling 6.

  FIG. 5 shows a sectional side view of the load cell (pressure detector) 8. The load cell 8 is integrally formed in a washer shape by a relatively thick inner ring portion 8i and an outer ring portion 8o, and a relatively thin intermediate strain portion 8m. The intermediate strain portion 8m includes a plurality of strain gauges 8s. ... with. As a result, when the pressure in the arrow Ff direction (forward direction) acts on the outer ring portion 8o and the pressure in the arrow Fr direction (rearward direction) acts on the inner ring portion 8i, the inner ring portion 8i. Is offset by about 0.1 to 0.2 [mm] in the axial direction with respect to the outer ring portion 8o, and the strain gauge 8s... The load cell 8 is disposed between the screw coupling 6 and the injection block 3 as shown in FIG. Reference numeral 44 denotes a protrusion formed in a ring shape in the circumferential direction by raising a part on the rear end surface 8r of the inner ring portion 8i.

  When the load cell 8 is assembled, a flange-like stopper portion 41 projecting radially outward is provided at the front end position of the outer peripheral portion of the screw coupling 6, and the thrust bearing 13 and the load cell 8 are provided behind the stopper portion 41. The inner ring portion 8i, the angular ball bearing 14, and the cylindrical roller bearing 15x (second bearing 15) are sequentially loaded. At this time, the inner ring side spacer 45 is interposed between the inner ring 14i of the angular ball bearing 14 and the inner ring 15i of the cylindrical roller bearing 15x, and the outer ring side spacer 46 is interposed between the outer ring 14o of the angular ball bearing 14 and the outer ring 15o of the cylindrical roller bearing 15x. 4 and the thickness Lo of the outer ring side spacer 46 is made thinner than the thickness Li of the inner ring side spacer 45, as shown in FIG. Thereby, since predetermined | prescribed greasing space can be ensured, greasing can fully and effectively be performed. Since the outer ring side spacer 46 does not substantially have a spacer function, the outer ring side spacer 46 is formed by making the thickness Lo of the outer ring side spacer 46 thinner than the thickness Li of the inner ring side spacer 45. This includes cases where it is not used.

  Further, as shown in FIG. 4, a gap Gs having a predetermined interval Ls is provided between the angular ball bearing 14 and the injection block 3. Thereby, generation | occurrence | production prevention and reduction of frictional resistance by the angular ball bearing 14 are realizable more effectively. Accordingly, the screw coupling 6 on the rear end face side of the load cell 8 is supported by the injection block 3 substantially only through the cylindrical roller bearing 15x. Further, since the rear end surface 8r of the inner ring portion 8i has a protrusion 44 that is partly raised and integrally formed, the outer ring 14o of the angular ball bearing 14 is brought into contact with the protrusion 44, and on the other hand, The thrust bearing 13 is brought into contact with the front end face 8f of the inner ring portion 8i.

  A screw portion is formed at the rear end position of the outer periphery of the screw coupling 6, and the bearing nut 16 is screwed onto the screw portion, whereby the outer periphery of the screw coupling 6 between the bearing nut 16 and the stopper portion 41. The thrust bearing 13, the load cell 8, the angular ball bearing 14 and the cylindrical roller bearing 15x loaded on the top are fixed. At this time, the bearing nut 16 is brought into contact with the inner ring 15i of the cylindrical roller bearing 15x. Further, an inner ring side spacer 42 is interposed between the inner ring 15i of the cylindrical roller bearing 15x and the bearing nut 16, and an outer ring side spacer 43 is interposed between the outer ring 15o of the cylindrical roller bearing 15x and the ball nut 27n. Can be made thinner than the thickness of the inner ring side spacer 42.

  On the other hand, a stopper surface 47 is formed by providing a step in the inner peripheral portion of the support hole 3s of the injection block 3, and this stopper surface 47 is brought into contact with the rear end surface of the outer ring portion 8o in the load cell 8 and is separately provided. The fixed block 48 is inserted into the inside of the front end opening of the injection block 3 and brought into contact with the front end surface of the outer ring portion 8o. Thereby, the fixed block 48 covers the outer side of the thrust bearing 13, and the outer ring portion 8 o is sandwiched and fixed between the fixed block 48 and the injection block 3.

  By assembling the load cell 8, the thrust bearing 13, the angular ball bearing 14 and the cylindrical roller bearing 15x in this way, the optimum configuration of the drive mechanism 1 can be realized. In particular, the basic effect of the drive mechanism 1, that is, the bearing The detection accuracy and reliability are improved by eliminating the influence of both the preload and the injection block 3 due to the tightening of the nut 16, and furthermore, high-precision management and pre-processing and assembly of the injection block 3 and the like are possible. It can contribute to facilitating parts manufacturing and mechanism assembly by not being required.

  A cylindrical roller bearing 18 is interposed between the injection block 3 and the screw coupling 6 on the front end face 8 f side of the load cell 8, that is, between the inner peripheral front end of the fixed block 48 and the stopper portion 41 of the screw coupling 6. . Thereby, the bad influence (screw misalignment of a screw etc.) by the tensile load of the radial direction provided to the screw coupling 6 can be prevented more reliably.

  On the other hand, as shown in FIGS. 1 and 3, the injection block 3 is provided with a pressure adjusting means P that presses the screw coupling 6 in the opposite direction to the tensile load Fp by the timing belt 5. The pressure adjusting means P includes a base body portion 11 provided with a tap hole 11n and an adjustment pressing bolt 12 screwed into the tap hole 11n. The base portion 11 is attached to the front surface portion 3f of the injection block 3 with two mounting bolts 51 and 52. Then, the adjustment pressing bolt 12 is screwed into the tap hole 11 n provided in the base portion 11, and the peripheral surface exposed to the outside of the fixed block 48 can be contacted (pressed) by the tip portion of the adjustment pressing bolt 12. The rear end surface of the adjustment pressing bolt 12 is formed with a locking portion that can be operated by rotating the adjustment pressing bolt 12 by locking a bit (jig) such as a driver.

  Therefore, the tip of the adjustment pressing bolt 12 can indirectly press the screw coupling 6, and the shaft center of the adjustment pressing bolt 12 is the center of the drive pulley 33 and the center of the driven pulley 34 as shown in FIG. 3. And the tip of the adjustment pressing bolt 12 is arranged with the center direction of the driven pulley 34 directed. This direction (orientation) is opposite to the tensile load Fp due to the timing belt 5. Note that the base body 11 and the adjustment pressing bolt 12 also serve as a position adjusting portion Pm that can adjust the pressing position Xp that presses the screw coupling 6. In addition, in the drawing, 53 indicates a lock nut screwed to the adjustment pressing bolt 12, and 49... Indicate fixing bolts provided at a plurality of positions for fixing the fixing block 48 to the injection block 3.

  Next, the function (action) of the drive mechanism 1 according to the present embodiment will be described with reference to FIGS.

  First, in the drive mechanism 1, if the bearing nut 16 is tightened, preload is applied to the thrust bearing 13, the angular ball bearing 14, and the cylindrical roller bearing 15 x, and the inner ring portion 8 i of the load cell 8 is the outer periphery of the screw coupling 6. Fixed on the part. In this case, the preload does not affect the intermediate strain generating portion 8m that detects the pressure. Further, the outer ring portion 8o of the load cell 8 is fixed only to the injection block 3, and the force for fixing the outer fitting portion 8o does not affect the intermediate strain portion 8m.

  Therefore, as shown in FIG. 6, the pressure in the direction of arrow Fr applied from the screw 29 is applied to the front end face 8f of the inner ring portion 8i of the load cell 8 via the screw coupling 6 (stopper portion 41) and the thrust bearing 13. To be added. On the other hand, since the position of the outer ring portion 8o of the load cell 8 is regulated by the injection block 3, the reaction pressure against the pressure applied from the screw 29 is applied from the direction of the arrow Ff and passes through the stopper surface 47 of the injection block 3. To the rear end surface 8r of the outer ring portion 8o. At this time, since the inner ring portion 8i to which the pressure in the direction of the arrow Fr is applied contacts only the outer ring 14o of the angular ball bearing 14, relative displacement (offset) relative to the rear of the inner ring portion 8i is allowed. Therefore, a strain (deflection) corresponding to the pressure is generated in the intermediate strain generating portion 8m, and this strain is detected as a pressure by the strain gauges 8s attached to the intermediate strain generating portion 8m. Since the output of the strain gauges 8s is not affected by the preload and the presence of the injection block 3, it is proportional to the pressure applied from the screw 29.

  Further, the drive mechanism 1 having such a configuration has a screw cup via an angular contact ball bearing 14 and a bearing portion 7 using a cylindrical roller bearing 15x arranged side by side on the angular contact ball bearing 14 by the inner peripheral portion of the injection block 3. Since the ring 6 is rotatably supported, even if the radial tension load Fp shown in FIG. 6 is applied to the screw coupling 6 by using the timing belt 5 for the rotation drive unit 4, The misalignment of the screw 29 can be effectively prevented. Therefore, generation | occurrence | production of the galling of the screw 29 with respect to the heating cylinder 28 can be avoided, and durability improvement can be aimed at by ensuring smooth operation | movement and reducing abrasion. Furthermore, since the cylindrical roller bearings 15x arranged side by side with the angular ball bearings 14 receive the radial tensile load Fp, the angular ball bearings 14 that directly contact the load cell 8 generate galling and the frictional resistance against the injection block 3 in the axial direction. A problem that becomes large can be avoided, and the detection accuracy of the load cell 8 can be increased.

  On the other hand, the pressing position Xp for pressing the screw coupling 6 can be adjusted by the position adjusting portion Pm in the pressing adjusting means P. In this case, all of the fixing bolts 49 provided at a plurality of positions are loosened, and the lock nut 53 screwed to the adjustment pressing bolt 12 is loosened.

  Next, the adjustment pressing bolt 12 is operated by turning with a jig. At this time, a turning operation can be performed by locking a bit (jig) such as a driver to a locking portion formed on the rear end surface of the adjustment pressing bolt 12. By turning and operating the adjustment pressing bolt 12, the adjustment pressing bolt 12 moves forward and backward, and the position of the front end portion of the adjustment pressing bolt 12 that contacts the peripheral surface of the fixed block 48, that is, the pressing position Xp can be adjusted. . Since the tension load Fp is applied to the screw coupling 6 by the timing belt 5, if the pressing position Xp changes, the position of the screw coupling 6 also changes. Therefore, the screw cup can be adjusted by adjusting the pressing position Xp. The centering of the ring 6, that is, the axis of the screw 29 and the axis of the heating cylinder 28 can be matched.

  When the alignment is completed, all the fixing bolts 49, which have been temporarily loosened, are tightened, the fixing block 48 is fixed to the injection block 3, and the lock nut 53 is tightened to lock the adjustment pressing bolt 12 in the adjustment position.

  Thus, since the drive mechanism 1 according to the present embodiment is provided with the pressure adjusting means P that presses the screw coupling 6 in the opposite direction to the tensile load Fp due to the timing belt 5, the timing belt 5 is provided to the rotary drive unit 4. Even if it is the structure by which the tensile load Fp of the radial direction is provided to the screw coupling 6, the core shift | offset | difference of the screw 29 can be prevented effectively. Therefore, generation | occurrence | production of the galling of the screw 29 with respect to the heating cylinder 28 can be avoided, and durability improvement can be aimed at by ensuring smooth operation | movement and reducing abrasion. In particular, the pressure adjusting means P includes a base portion 11 that is attached to the injection block 3 by having a tap hole 11n, and an adjustment pressing bolt 12 that can be screwed into the tap hole 11n to press the screw coupling 6 at the tip portion. Since it can be configured, it can be implemented easily and at low cost with a small number of parts, and there is an advantage that it can be easily implemented by retrofitting or simple improvement to an existing injection molding machine.

  On the other hand, FIGS. 7 and 8 show a drive mechanism 1 according to a modified embodiment of the present invention. The drive mechanism 1 shown in FIG. 7 is a large-sized injection molding machine including an advance / retreat drive unit 2 in which a pair of ball screw mechanisms 101 and 102 are arranged on the left and right sides, which are rotationally transmitted from a screw advance / retreat drive motor (servo motor) (not shown). The case where it mounts in M is shown. In this case, the drive mechanism 1 is also large, but the basic configuration is the same as that shown in FIG. Therefore, since the basic configuration of the advance / retreat drive unit 2 is the same as that shown in FIG. 3, the configuration of the press adjusting means P in the modified embodiment shown in FIG. 7 is also the press adjusting means shown in FIGS. The same configuration as P can be adopted. Thus, the drive mechanism 1 according to the present invention can be similarly applied even when a part or all of the advance / retreat drive unit 2 and the rotation drive unit 4 are configured by a plurality of parts.

  Further, the drive mechanism 1 shown in FIG. 8 shows a modified embodiment of the bearing portion 7. In the drive mechanism 1 shown in FIG. 1, the bearing portion 7 is constituted by an angular ball bearing 14 arranged on the rear end face 8r side of the load cell 8 and a cylindrical roller bearing 15x arranged side by side on the angular ball bearing 14, and a fixed block 48 8 shows a case where the cylindrical roller bearing 18 is interposed between the front end of the inner circumferential portion of the screw coupling 6 and the stopper portion 41 of the screw coupling 6, but the drive mechanism 1 shown in FIG. 8 has a deep groove ball bearing 15y instead of the cylindrical roller bearing 15x. The (second bearing 15) is used, and a deep groove ball bearing 105 is used instead of the cylindrical roller bearing 18. Usually, in the case of a cylindrical roller bearing, there is a side that is difficult to increase in size from the technical aspect and cost. Therefore, the large-sized injection molding machine M may not be able to use the cylindrical roller bearing 15x or the cylindrical roller bearing 18, and the drive mechanism 1 shown in FIG. 8 is particularly useful in such a case.

  That is, the drive mechanism 1 shown in FIGS. 1 to 4 employs the pressure adjusting means P, and in addition to the angular contact ball bearing 14 and the cylindrical ball bearing 14 arranged side by side by the inner peripheral portion of the injection block 3. In order to employ a configuration in which the screw coupling 6 is rotatably supported via the bearing portion 7 using 15x, the timing belt 5 is used for the rotation driving portion 4 so that the screw coupling 6 has a radial tensile load Fp. Even if it is provided, the misalignment of the screw 29 can be prevented by an optimum form. However, in the case of a large injection molding machine M in which the cylindrical roller bearing 15x (18) cannot be used, the same function as that in the case of using the cylindrical roller bearing 15x (18) is exhibited by adopting the press adjusting means P. Can be made. 7 and 8, the same parts as those in FIGS. 1 to 4 are denoted by the same reference numerals to clarify the configuration, and detailed description thereof is omitted.

  Although the best embodiment has been described in detail above, the present invention is not limited to such an embodiment, and departs from the gist of the present invention in the detailed configuration, shape, material, quantity, numerical value, and the like. It can be changed, added, or deleted as long as it is not.

  For example, the configuration of the pressing adjustment means P is not limited to the illustrated configuration, and has a function of pressing the screw coupling 6 in the opposite direction with respect to the tensile load Fp by the timing belt 5, and the pressing position Xp. If it has the position adjustment part Pm which can be adjusted, the structure will not be ask | required. In particular, the case where the pressure adjusting means P is disposed on the injection block 3 has been shown. However, the pressure adjusting means P is provided on the fixed block 48 or the screw coupling 6 to press the injection block 3. Since the present invention exhibits the same function (action), the present invention is a concept including such a configuration. Moreover, although the case where the screw coupling 6 was indirectly pressed by the front-end | tip part of the adjustment pressing bolt 12 via the fixed block 48 was shown, the screw coupling 6 is directly pressed by the front-end | tip part of the adjustment pressing bolt 12. FIG. It may be a configuration. Furthermore, although the load cell 8 illustrated the type comprised by the washer type | mold which has the inner ring part 8i, the outer ring part 8o, and the intermediate strain part 8m, it does not exclude another shape. In this case, the shapes of the screw coupling 6 and the injection block 3 may be changed corresponding to the shape of the load cell 8. In addition, although the case where it applied to the electric injection molding machine was illustrated, it can apply similarly also to the injection molding machine by other drive formats, such as a hydraulic injection molding machine.

Sectional plan view showing the main part of the drive mechanism according to the best embodiment of the present invention, A partial cross-sectional plan view of an injection molding machine (injection device) provided with the drive mechanism, Front configuration diagram of the pressure adjusting means in the drive mechanism, A cross-sectional plan view of a bearing portion in the drive mechanism, A cross-sectional side view of a load cell used for the drive mechanism, Function (action) explanatory diagram of the drive mechanism, The front block diagram which shows the principal part of the drive mechanism which concerns on the modified embodiment of this invention, Sectional top view which shows the principal part of the drive mechanism which concerns on other modified embodiment of this invention, The block diagram which shows the principal part of the drive mechanism concerning background art,

Explanation of symbols

  1: drive mechanism, 2: forward / backward drive unit, 3: injection block, 4: rotation drive unit, 5: timing belt, 6: screw coupling, 7: bearing unit, 8: load cell, 8i: inner ring unit, 8o: Outer ring portion, 8m: Intermediate strain portion, 8f: Front end surface of load cell, 8r: Rear end surface of load cell, 11: Base portion, 11n: Tap hole, 12: Adjusting pressure bolt, 13: Thrust bearing, 14: Angular ball Bearing: 15: Second bearing, 15x: Cylindrical roller bearing, 15y: Deep groove ball bearing, 16: Bearing nut, Fa: Axial direction, Fp: Tensile load, M: Injection molding machine, Xp pressing position, Pm: Position adjustment section , P: pressure adjusting means, Ls: predetermined interval, Gs: gap

Claims (6)

  An injection block to which axial movement is transmitted from the advancing / retreating drive unit, and a screw coupling to which the rotation motion is transmitted via the timing belt of the rotation drive unit, and an inner peripheral portion of the injection block via the bearing unit In the drive mechanism of the injection molding machine that supports the screw coupling in a rotatable manner, the screw coupling is disposed on the injection block and presses the screw coupling in the opposite direction to the tensile load by the timing belt. A drive mechanism for an injection molding machine, comprising press adjusting means having a position adjusting unit capable of adjusting the press position.   The pressure adjusting means has a tapped hole, a base portion attached to the injection block, and an adjustment that can be screwed into the tapped hole and the tip portion can directly or indirectly press the screw coupling. The drive mechanism for an injection molding machine according to claim 1, further comprising a pressing bolt.   The drive mechanism for an injection molding machine according to claim 1, further comprising a load cell for detecting an axial pressure between the injection block and the screw coupling.   A thrust bearing is interposed between the screw coupling and the front end face of the load cell, and the bearing portion is composed of an angular ball bearing arranged on the rear end face side of the load cell and a second bearing arranged side by side on the angular ball bearing. The drive mechanism for an injection molding machine according to claim 3.   The load cell is configured in a washer shape having an inner ring portion, an outer ring portion, and an intermediate strain portion, and the thrust bearing, the inner ring portion, the angular ball bearing, and the second bearing are screw-coupled by a bearing nut. 5. The drive mechanism of an injection molding machine according to claim 4, wherein the outer ring portion is fixed to the injection block.   6. The drive mechanism for an injection molding machine according to claim 4, wherein the second bearing is a cylindrical roller bearing or a deep groove ball bearing.

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