JP2021160036A - Cylinder head press-in method - Google Patents

Abstract

To provide a cylinder head press-in method capable of tilting, and accurately positioning and holding a holding part and a cylinder head held by the holding part for a long period.SOLUTION: When a press-in device which includes a holding part 4 capable of holding a cylinder head W, a motor 5 capable of tilting the holding part 4 holding the cylinder head W at a prescribed angle θ1(θ2), and receiving members 6, 7 for receiving a press-in force contacting the holding part 4 and operating the cylinder head W when a press-in member P1(P2) is pressed in the cylinder head W is used to press the press-in the member P1(P2) in the cylinder head W, rotary driving of the motor 5 is stopped while the cylinder head W is tilted by the motor 5 at the prescribed angle θ1(θ2), and then presses the press-in member P1(P2) in the cylinder head W.SELECTED DRAWING: Figure 1

Description

The present invention relates to a cylinder head press-fitting method, and more particularly to a method for press-fitting a press-fitting member such as a valve seat or a valve guide into a cylinder head.

When performing this type of press-fitting, conventionally, a holding portion that holds a cylinder head that is a press-fitting member and can be tilted around its longitudinal axis and a holding portion that holds the cylinder head are tilted. A press-fitting device including a cylinder portion for causing the cylinder portion and a tilt regulating portion for restricting tilting of the holding portion exceeding a predetermined angle is used (see, for example, Patent Document 1).

The press-fitting operation of the press-fitting member (valve seat or valve guide) to the cylinder head using the press-fitting device having the above configuration is performed as follows, for example. That is, first, after attaching the cylinder head to the holding portion, the cylinder portion is driven to tilt the holding portion. At this time, when the holding portion comes into contact with the tilt regulating portion arranged at a predetermined position, the holding portion is held in a state of being tilted at a predetermined angle, and the posture of the cylinder head held by the holding portion is predetermined. Is set to the angle of. After that, the corresponding press-fitting member is lowered along the vertical direction and press-fitted into the corresponding press-fitting portion (press-fitting hole) of the cylinder head to press-fit the press-fitting member into the cylinder head.

Japanese Unexamined Patent Publication No. 2009-233813

According to the press-fitting device having the above configuration, the tilt angle of the holding portion is set by the holding portion coming into contact with the tilt restricting portion, so that the cylinder portion does not require high position accuracy. Therefore, a hydraulic cylinder capable of obtaining a relatively large output and driving speed is used for the cylinder portion. However, when positioning the holding portion as described above, the holding portion is tilted at high speed by the hydraulic cylinder and collides with the tilt regulating portion each time the positioning work is performed. Wear becomes a problem. Since the position where the tilt of the holding portion is regulated changes due to the wear of the tilt regulating portion, there arises a problem that it becomes difficult to position the cylinder head at an accurate tilt angle.

Therefore, for example, a means for holding the holding portion at a predetermined tilt angle by rotating the holding portion around the longitudinal axis thereof with a motor instead of the hydraulic cylinder can be considered. A motor (particularly a servomotor) seems to be promising as an alternative means because the holding portion can be stopped at a predetermined tilt angle without mechanically restricting the tilting of the holding portion. However, in this type of press-fitting operation, a press-fitting member such as a valve seat is press-fitted into the cylinder head by press-fitting on the order of several tons. Therefore, when the holding part is rotated by the motor to hold it at a predetermined angle, it is necessary for the motor to receive a huge press-fitting load, but it is a reality that a general-purpose motor receives a press-fitting load on the order of several tons. Not the target.

In view of the above circumstances, it is a technique to be solved in the present specification to provide a cylinder head press-fitting method capable of tilting the holding portion and the cylinder head held by the holding portion for accurate positioning and holding. Make it an issue.

The solution to the above problems is achieved by the cylinder head press-fitting method according to the present invention. That is, this press-fitting method hits the holding portion capable of holding the cylinder head, the motor capable of tilting the holding portion holding the cylinder head at a predetermined angle, and the holding portion when the press-fitting member is press-fitted into the cylinder head. When press-fitting a press-fitting member into the cylinder head using a press-fitting device provided with a receiving member for receiving a press-fitting member that comes into contact with the cylinder head and acts on the cylinder head, the cylinder head is tilted at a predetermined angle by the motor. It is characterized by stopping the rotational drive and then press-fitting the press-fitting member into the cylinder head.

As described above, in the cylinder head press-fitting method according to the present invention, while the tilt angle of the cylinder head is set by the motor, the load (press input) acting on the cylinder head at the time of press-fitting is received by the receiving member provided separately from the motor. I did. According to this method, the cylinder head can be accurately positioned at a predetermined angle by the motor. On the other hand, by performing the press-fitting operation after stopping the rotational drive of the motor, the load acting on the motor can be reduced as much as possible, and most of the press-fitting input acting on the cylinder head at the time of press-fitting can be received by the member. Further, since the holding portion comes into contact with the receiving member by receiving the pressure input from the state of being tilted at a predetermined angle by the motor, the holding portion and the receiving member can be received at a very short distance at the time of press fitting. Therefore, the pressure input can be received as a substantially static load. Therefore, even with continuous use, damage to the motor and the receiving member can be suppressed, and the cylinder head can be accurately positioned and held for a long period of time. Therefore, the press-fitting operation to the cylinder head can be performed with high accuracy for a long period of time. Further, by tilting the holding portion with the motor, for example, the holding portion can be easily held in a horizontal posture, so that teaching is facilitated when replacing the cylinder head using a robot arm, for example, other than press-fitting work. It is also possible to improve the efficiency of the work.

As described above, according to the present invention, the holding portion and the cylinder head held by the holding portion can be accurately positioned and held at a predetermined angle, whereby press-fitting to the cylinder head can be performed with high accuracy over a long period of time. It becomes possible to do.

It is a front view of the main part of the press-fitting device for a cylinder head which concerns on one Embodiment of this invention. It is a side view of the main part of the press-fitting device for a cylinder head shown in FIG. It is a flowchart which shows an example of the cylinder head press-fitting method using the press-fitting apparatus shown in FIG. FIG. 3 is a side view of a main part showing a state in which the cylinder head is mounted on the holding portion in a state where the holding portion is in a horizontal posture in the cylinder head mounting step S1 shown in FIG. FIG. 3 is a side view of a main part showing a state in which the holding part is tilted at a predetermined angle by a motor in the first positioning step S2 of the cylinder head shown in FIG. FIG. 3 is a side view of a main part showing a state of a holding portion when the valve seat is press-fitted in the first press-fitting step S3 of the valve seat shown in FIG.

Hereinafter, a cylinder head press-fitting method according to an embodiment of the present invention will be described with reference to the drawings. In this embodiment, a case where the valve seat is press-fitted into the cylinder head will be described as an example.

FIG. 1 is a front view of a main part of the cylinder head press-fitting device 1 according to the present invention. As shown in the figure, the cylinder head press-fitting device 1 is provided with a press-fitting generation unit 2 and a plurality of punches 31 and 32 for press-fitting valve seats P1 and P2 serving as press-fitting members into the cylinder head W. It includes a punch unit 3, a holding portion 4 that holds the cylinder head W and is configured to tilt around its longitudinal axis, a motor 5, and receiving members 6 and 7. The details of each component will be described below.

The press-fitting unit 2 has a plurality of press-fitting rams 22 arranged on the gantry 21 and a press-fitting device 23 for applying a press-fitting ram 22 to the press-fitting ram 22. Here, the pressure input applying device 23 is configured so that a pressure input in the vertical direction can be applied to each of the three press-fitting rams 22 arranged in parallel. Any drive source can be used as the pressure input applying device 23, and for example, a known drive source such as a hydraulic cylinder or a press servo mechanism can be used. Further, both the press-fitting ram 22 and the press-fitting device 23 are integrally provided on the support portion 24, and are provided in the front-rear direction (left-right direction in FIG. 2) by a guide rail 25 (LM guide or the like) provided on the gantry 21. It is configured to be movable to. Here, the drive device 26 is provided behind the support portion 24 (the right portion in FIG. 2), and the plurality of press-fitting rams 22 and the pressure input imparting device 23 integrally supported by the support portion 24 by the drive device 26 are moved. I try to let you. Of course, if the press-fitting ram 22 and the press-fitting device 23 are arranged, for example, three in two rows according to the arrangement of the exhaust side punch 31 and the intake side punch 32 described later, the moving mechanism is unnecessary. be.

As described above, the punch unit 3 has a plurality of punches 31 and 32 integrally, and is configured to be slidable on the guide rail 34 by, for example, a uniaxial servo mechanism 33. Each of the punches 31 and 32 is formed separately from the press-fitting ram 22, and the press-fitting members (valve seats P1 and P2) held at the lower ends thereof by receiving the force from the press-fitting ram 22 can be press-fitted into the cylinder head W. It is arranged at a position (height). Further, for example, in FIG. 2, the air cylinders 35 arranged between the punches 31 and 32 adjacent to each other in the left-right direction exert a force different from the pressure input applied from the press-fitting ram 22 to the punches 31 and 32. Can be given to. Both the punches 31 and 32 are supported so as to be slidable in the vertical direction by the holder 36 provided in the punch unit 3.

The holding portion 4 is provided with a plate 41 for sandwiching the cylinder head W placed on the upper surface thereof. Further, the holding portion 4 is provided with one or a plurality of pins 42 that can be positioned by being inserted into the cylinder head W. Therefore, by attaching the plate 41 with the cylinder head W inserted into the positioning pin 42, the cylinder head W is positioned and held with respect to the holding portion 4. Further, as shown in FIG. 1, a pair of bearing portions 43, 43 capable of rotationally supporting the holding portion 4 around the longitudinal axis X1 are provided at both ends of the holding portion 4 in the longitudinal direction. In this way, the holding portion 4, the plate 41, the pin 42, and the pair of bearing portions 43, 43 form a rotation holding mechanism for the cylinder head W.

A motor 5 capable of rotating (tilting) the holding portion 4 around the longitudinal axis X1 of the holding portion 4 is disposed on one end side in the longitudinal direction of the holding portion 4. Here, the motor 5, to the extent possible tilt the holder 4 in a state of holding the cylinder head W, in other words, capable of outputting the torque of the degree capable of tilting the holding portion 4 (e.g. 10 1 ^Nm order or higher) To the extent that any type of motor can be applied. For example, from the viewpoint of position accuracy, a servomotor is preferable. Similarly, from the viewpoint of position accuracy, the motor may have a braking function that mechanically brakes the rotating shaft when the power is turned off. Of course, from the viewpoint of reducing the influence of the press-fitting load described later on the motor 5 as much as possible, the motor may have a structure that does not have the above-mentioned braking function (the rotating shaft is in a rotation-free state when the power is turned off).

Here, as shown in FIG. 5 or FIG. 6 described later, the tilt angle θ1 (θ2) of the holding portion 4 by the motor 5 is set to a size equal to the valve angle of the cylinder head W to be held. That is, it is preferable to set the tilt angle θ1 (θ2) according to the type of the cylinder head W to be press-fitted or according to the types of valve seats P1 and P2 to be press-fitted. The tilt angle θ1 (θ2) of the holding unit 4 may be set by controlling the rotational drive of the motor 5 by the control unit 51 electrically connected to the motor 5.

A protruding portion 44 projecting downward is formed in the lower portion of the holding portion 4, and a pair of receiving members 6 and 7 capable of contacting the protruding portion 44 are provided below the holding portion 4. .. Here, each of the receiving members 6 and 7 has a plurality of receiving portions 61 and 71 projecting in a direction facing the projecting portion 44 (see FIG. 2). These receiving portions 61 and 71 are composed of, for example, bolts. Then, as will be described later, these plurality of receiving portions 61 and 71 press-fit the press-fitting members (valve seats P1 and P2 in this case) into the holding portion 4 in a state of being positioned and held at a predetermined angle θ1 (θ2) by the motor 5. At that time, the position of the receiving portion 61 is adjusted so that the protruding portion 44 comes into contact with the receiving portion 61. Specifically, as shown in FIGS. 5 and 6, the holding portion 4 is tilted by the motor 5 to be positioned and held at a predetermined angle θ1, and between the protruding portion 44 and the receiving portions 61, 71. The mounting positions of the receiving portions 61 and 71 with respect to the bases 62 and 72 are adjusted so that the slight gaps d1 and d2 are formed. As an example, the bases of the receiving portions 61 and 71 so that the facing distances d1 and d2 are, for example, 0.005 mm or more and 0.1 mm or less, preferably 0.01 mm or more and 0.05 mm or less. The mounting position with respect to the bases 62 and 72 is adjusted.

Hereinafter, an example of a cylinder head press-fitting method using the cylinder head press-fitting device 1 having the above configuration will be described.

As shown in FIG. 3, for example, the cylinder head press-fitting method according to the present embodiment includes a cylinder head mounting step S1, a cylinder head first positioning step S2, a valve seat first press-fitting step S3, and a cylinder head. The second positioning step S4 and the second press-fitting step S5 of the valve seat are provided. Hereinafter, details will be described with reference to steps S1 to S3.

(S1) Mounting Step First, by turning on the power of the motor 5 and driving the motor 5 to rotate, the holding portion 4 is tilted and held in a horizontal posture (see FIG. 4). After that, the cylinder head W to be press-fitted is carried in from the outside of the press-fitting device 1 to a predetermined position on the holding portion 4 by a robot arm (not shown), and the cylinder head W is carried by the plate 41 and the clamp pins 42 and 42. It is fixed to the holding portion 4. When the motor 5 has a brake function, the power of the motor 5 is temporarily turned off when the holding portion 4 is placed in the horizontal posture, and the holding portion 4 is held in the horizontal posture by the braking function of the motor 5. The cylinder head W may be attached at.

(S2) First Positioning Step After attaching the cylinder head W to the holding portion 4 as described above, the cylinder head W is positioned. Specifically, as shown in FIG. 5A, the longitudinal axis X1 passing through the tilt center Ot is driven by rotating the motor 5 while the power of the motor 5 is continuously turned on (see FIG. 1). The holding portion 4 is rotated around the cylinder head W to tilt the cylinder head W to an angle θ1 at which the valve seat P1 can be press-fitted by the corresponding punch (here, the exhaust side punch 31). Of course, when the power supply of the motor 5 is turned off when the cylinder head W is attached by using the brake function of the motor 5, the cylinder head W is positioned as described above after the power supply of the motor 5 is switched on. Further, at this time, the press-fitting ram 22 is moved on a substantially one-row arrangement line of each exhaust-side punch 31 of the punch unit 3 so that a pressure input can be applied to the exhaust-side punch 31. In the state where the cylinder head W is positioned, the protruding portion 44 of the holding portion 4 and one receiving member 6 are in a non-contact state. Specifically, the distance between the one receiving member 6 and the protruding portion 44 is opposed to each other. The receiving portion 61 and the protruding portion 44 are slightly separated from each other so that d1 is within the above-mentioned range.

(S3) First Press-fitting Step After positioning the cylinder head W as described above, the exhaust side punch 31 holding the corresponding valve seat P1 at the tip is arranged at a predetermined position above the cylinder head W. In this state, the axis line Xe of the exhaust valve of the cylinder head W (see FIG. 1) and the press-fitting direction line X2 of the exhaust side punch 31 for press-fitting the corresponding valve seat P1 (see FIG. 1) coincide with each other. .. Therefore, by driving the air cylinder 35 from this position and lowering all the exhaust side punches 31 (three exhaust side punches 31 in this embodiment), the valve seat P1 corresponding to the press-fitting position in the cylinder head W is released. be introduced. At this time, the valve seat P1 is temporarily pressed at the press-fitting position with positioning. Then, from this state, the pressure input applying device 23 is driven to push the press-fitting ram 22 located above the exhaust side punch 31 downward. As a result, as shown in FIG. 6A, the exhaust side punch 31 receives the press-fitting input from the press-fitting ram 22, and the valve seat P1 in the temporarily pressed state is press-fitted and fixed to the cylinder head W.

Further, by this press-fitting operation, the holding portion 4 receives a press-fitting input from the exhaust side punch 31. At this time, since the press-fitting direction line X2 of the exhaust side punch 31 is offset from the tilt center Ot of the holding portion 4, the holding portion 4 has a predetermined direction, and in the case shown in FIG. 6A, the torque is counterclockwise. Receive. As a result, the protruding portion 44 formed in the lower portion of the holding portion 4 comes into contact with the receiving portion 61 of the receiving member 6 facing each other via the predetermined interval d1. Therefore, most of the pressure input received by the holding portion 4 from the exhaust side punch 31 is received by one receiving member 6 (receiving portion 61) that comes into contact with the protruding portion 44. When positioning the cylinder head W using the motor 5 having a braking function, the above-mentioned press-fitting operation may be performed with the power supply of the motor 5 turned off. Normally, this type of brake is only provided with a braking force capable of braking a rotating shaft that is rotating by inertia after the power is turned off. Therefore, even if the rotating shaft of the motor 5 is fixed by the brake after the power is turned off, the load on the motor 5 side is minimized so that most of the pressure input is received by the member 6 (receiving portion 61). It becomes possible.

(S4) Second Positioning Step Subsequently, as shown in FIG. 5B, the motor 5 is rotationally driven in the direction opposite to that in the first positioning step S2, so that the longitudinal axis X1 passing through the tilt center Ot (S4) (See FIG. 1) The holding portion 4 is rotated around the cylinder head W to tilt the cylinder head W to an angle at which the valve seat P2 can be press-fitted by the corresponding punch (here, the intake side punch 32). Further, at this time, the press-fitting ram 22 is moved on a substantially one-row arrangement line of each intake-side punch 32 of the punch unit 3 so that a pressure input can be applied to the intake-side punch 32. In the state where the cylinder head W is positioned, the protruding portion 44 of the holding portion 4 and the receiving members 6 and 7 are in a non-contact state, and specifically, the distance between the other receiving member 7 and the protruding portion 44 is opposed to each other. The receiving portion 71 and the protruding portion 44 are adjusted to be slightly separated from each other so that d2 has a predetermined size.

(S5) Second Press-fitting Step After positioning the cylinder head W as described above, the intake side punch 32 holding the corresponding valve seat P2 at the tip is arranged at a predetermined position above the cylinder head W. In this state, the axis line Xi of the exhaust valve of the cylinder head W (see FIG. 1) and the press-fitting direction line X3 of the intake side punch 32 for press-fitting the corresponding valve seat P2 (see FIG. 1) coincide with each other. .. Therefore, by driving the air cylinder 35 from this position and lowering all the intake side punches 32, the valve seat P2 corresponding to the press-fitting position in the cylinder head W is introduced. At this time, the valve seat P2 is temporarily pressed at the press-fitting position with positioning. Then, from this state, the press-fitting device 23 is driven to push the press-fitting ram 22 located above the intake side punch 32 downward. As a result, as shown in FIG. 6B, the intake side punch 32 receives the press-fitting input from the press-fitting ram 22, and the valve seat P2 in the temporarily pressed state is press-fitted and fixed to the cylinder head W.

Further, by this press-fitting operation, the holding portion 4 receives the press-fitting from the intake side punch 32. At this time, since the press-fitting direction line X3 of the intake side punch 32 is offset from the tilt center Ot of the holding portion 4, the holding portion 4 exerts a clockwise torque in a predetermined direction in the case shown in FIG. 6B. receive. As a result, the protruding portion 44 formed in the lower portion of the holding portion 4 comes into contact with the receiving portion 71 of the receiving member 7 facing each other via the predetermined interval d2. Therefore, most of the pressure input received by the holding portion 4 from the intake side punch 32 is received by the other receiving member 7 (receiving portion 71) that comes into contact with the protruding portion 44. Also in this case, after positioning the cylinder head W using the motor 5, the above-mentioned press-fitting operation may be performed with the power supply of the motor 5 turned off.

As described above, in the cylinder head press-fitting method according to the present embodiment, the tilt angle of the cylinder head W is set by the motor 5, while the load (pressure input) acting on the cylinder head W during press-fitting is different from that of the motor 5. It was made to receive by the receiving member 6 (7) provided separately. According to this method, the cylinder head W can be accurately positioned at a predetermined angle θ1 (θ2) by the motor 5. On the other hand, by performing the press-fitting operation after stopping the rotational drive of the motor 5, the load acting on the motor 5 is reduced as much as possible, and most of the press-fitting force acting on the cylinder head W at the time of press-fitting is received by the member 6 (7). Can receive. Further, since the holding portion 4 comes into contact with the receiving member 6 (7) by receiving the pressure input from the state of being tilted to the predetermined angles θ1 and θ2 by the motor 5, the holding portion 4 and the receiving member 6 (7) are brought into contact with each other at the time of press fitting. ) And can be received at a very short distance. Therefore, the pressure input can be received as a substantially static load. Therefore, even after continuous use, damage to the motor 5 and the receiving members 6 and 7 can be suppressed, and the cylinder head W can be accurately positioned and held for a long period of time. Therefore, the press-fitting operation to the cylinder head W can be performed with high accuracy for a long period of time. Further, by tilting the holding portion 4 with the motor 5, for example, the holding portion 4 can be easily held in a horizontal posture, so that teaching becomes easy, for example, when the cylinder head W is replaced using the robot arm. It is also possible to improve the efficiency of work other than press-fitting work.

Although one embodiment of the cylinder head press-fitting method according to the present invention has been described above, the present invention is not limited to this mode, and it goes without saying that any specific form can be adopted within the scope of the present invention. ..

For example, in the above embodiment, the motor 5 is connected to the holding portion 4 capable of holding the cylinder head W, and the holding portion 4 is tilted by the rotational drive of the motor 5, so that the cylinder head is held by the holding portion 4. The case where W is tilted integrally has been illustrated, but of course, it is not limited to this. For example, although not shown, a connecting shaft is attached to the cylinder head W, the rotating shaft of the motor 5 is connected to the connecting shaft, the cylinder head W to which the connecting shaft is attached is attached to the holding portion 4, and then the motor 5 The cylinder head W may be tilted by rotational drive.

Further, in the above embodiment, the receiving portions 61 and 71 arranged below the holding portion 4 and composed of a plurality of bolts are brought into contact with the protruding portions 44 protruding downward of the holding portion 4 at the time of press fitting. The case where the pressure input is received by each of the receiving portions 61 and 71 has been illustrated, but of course, the case is not limited to this. That is, it is desirable that the forms of the receiving portions 61 and 71 constituting the receiving members 6 and 7 are appropriately set according to the contact mode including the contact position with the holding portion 4.

Further, for example, in the above embodiment, the case where the valve seats P1 and P2 are press-fitted into the cylinder head W has been described, but the present invention is not particularly limited to this component. It goes without saying that the cylinder head press-fitting method according to the present invention can be applied as long as it is a press-fitting member such as a valve guide that is press-fitted into the cylinder head.

1 Cylinder head press-fitting device 2 Press-fitting device 3 Punch unit 4 Holding section 5 Motors 6, 7 Receiving member 21 Stand 22 Press-fitting ram 23 Press-fitting ram 23 Pressure input applying device 26 Drive device 31 Exhaust side punch 32 Intake side punch 35 Air cylinder 41 Plate 42 Pin 43, 43 Bearing part 44 Protruding part 51 Control part 61, 71 Receiving member 62,72 Base d1, d2 Opposing distance Ot Tilt center (holding part)
P1, P2 Valve seat W Cylinder head X1 Longitudinal axis X2 Press-fit direction line X3 Press-fit direction line θ1, θ2 Tilt angle

Claims (1)

A holding portion capable of holding a cylinder head, a motor capable of tilting the holding portion holding the cylinder head at a predetermined angle, and a cylinder that comes into contact with the holding portion when a press-fitting member is press-fitted into the cylinder head. When press-fitting the press-fitting member into the cylinder head using a press-fitting device provided with a receiving member for receiving a press-fitting force acting on the head,
A cylinder head press-fitting method in which the rotational drive of the motor is stopped in a state where the cylinder head is tilted by the motor at the predetermined angle, and then the press-fitting member is press-fitted into the cylinder head.

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