JPH06509753A - Joining body parts - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed description of the invention] Joining body parts The present invention utilizes the compressive force obtained by each of the plurality of connecting bolts passing through the body portion. - a joint for joining body parts together by holding the facing parts through; , the residual tensile stress is maintained by the bolt head and nut in contact with the flange. This relates to a type of joining.

In particular, but not exclusively, the present invention provides flanges that are held facing each other by compressive force; It is also a body that has flanges that are not necessarily in mutual contact before being joined by Porto. It also relates to bodies such as turbine casings, and many other parts. A large number of holes and fine pitches are required to produce appropriate and uniform flange compression force. Due to the force required to This relates to a type of body that requires the use of bolts of a certain diameter.

In heavy industry, turning a nut that is screwed into a bolt usually does not It is well known that it is difficult to obtain a constant tensile stress.The reason is that friction and There are often accessibility issues and also the residuals obtained for different bolts. Tension LL: Differences in forces can cause individual overstressed bolts to fail or flange Leakage paths may occur where bolt stress is too low or distortion exceeds allowable limits. This is because there are things that can happen.

Due to these circumstances, in order to give residual stress to the flange connection bolt, the longitudinal direction of the bolt should be By creating a large tensile stress between both ends of the bolt along the 1- Screw in the bolt along the threaded part so that the nut touches one flange and the port 1 by bringing the head into contact with the other flange and then removing the stress source. As a result, the bolt contracts, and the residual stress is maintained by the bolt head and nut. It is known to transmit residual or compressive forces into the flange.

Through the relationship between the elongation of PoAl- and the tensile stress, the nut will eventually produce a certain residual stress. The initial tensile stress can be selected to occupy the position where the stress occurs.

For this purpose, only a small space remains for the use of complex bolting devices. When joining a body such as a turbine casing, it is known to do the following: be. That is, using a bolt with an axial cavity extending between both ends of the bolt, Heat the bolt with a heater through the cavity, expand it by a predetermined length in the vertical direction, and then tighten the bolt. The tube is positioned and then cooled to produce a predetermined residual stress due to contraction as it cools. It makes you feel the same.

A bolt having such an axial cavity and suitable for joining two such body parts Although bolts can be used for other purposes, they are referred to herein as joint bolts. would be convenient.

When this type of joint bolt is extended axially, instead of due to thermal expansion or In addition to thermal expansion, "mechanical" forces can be used. This force can be applied to a hydraulic ram or , applied by a load cell, preferably configured as a hydraulic stress generator. It is most practical to do so.

Bolts equipped with hydraulic stress generators that provide such stretching forces directly between the ends of the bolt. This is considered a self-stress-generating joint bolt.

An example of a self-stressing bolt of this type is disclosed in US-A-4884934. There is. For this bolt, the actuating rod runs along the longitudinal center blind hole of the bolt. A large tensile stress is applied between both ends of the bolt by a hydraulic stress generator having the bolt.

One end of the actuating rod is supported in the internal head area, and the other end is formed at the other end of the hole. The piston acts as a piston in a cylinder. Hydraulic pressure is applied to the cylinder. hydraulic pressure The longitudinal force exerted by the bolt exerts a tensile stress through both ends of the bolt. act and react in such a way that On the other hand, the nut can be attached to the bolt shaft with a small torque. It is lowered along the same line until it reaches a predetermined position and comes into contact with the body. Then the hydraulic pressure is released. The residual stress is maintained by the bolt head and nut. Even in this configuration , heat has been used in combination with hydraulic stress generators.

Another example of a self-stressing joint bolt is described in patent specification CB+382191. This patent relates to a so-called radial fit bolt.

According to the description, this bolt has an integral head at one end of an elongated shaft; At least the other end of the nut has a thread cut into it into which the nut is screwed. This bolt is It also has a blind hole extending in the axial direction. This blind hole opens at the end of the head and It extends near the other end. The operating rod is placed inside the blind hole, and the hydraulic pressure is applied to the head end. It is possible to install a ram. This causes the hydraulic pressure to create a tensile stress between the ends of the bolt. This tensile stress causes the bolt shaft to elongate and contract in the radial direction, resulting in a smaller diameter. Allows entry into the small hole and releases the hydraulic pressure to ensure an interference fit for the bolt. arise.

In this specification, the term "joint bolt" refers to self-stressing bolts of the type outlined above. Refers only to the joint bolt, and is due to the reaction of the tensile force into the body that causes the bolt to protrude. Therefore, it does not refer to bolts that generate stress. In addition, “hydraulic stress generator” ” extends along the center cavity of a joining bolt and applies stress between the ends of the bolt. Used to refer to the hydraulic device and the actuating rod that cause the operation to occur.

In order to directly apply tensile stress between both ends of the shaft of a self-stress-generating joint bolt, In general, it does not matter whether the hydraulic stress is generated from either end of the shaft. That's true.

Furthermore, as used herein, the term "bolt" is used to refer to a joining bolt. or, if not, a radially extending flange or shank. (a “head” with an extension that occupies a position in contact with the body) Used for bolts meaning an elongated shaft with a In the latter case, functional The bolt head is integral with the shank or has a single head at one location along the shank. instead of, or in addition to, having a threaded nut with an integral head and a flange on an elongated shank. It is located at a different location from the physical end.

When two body parts are joined at their flanges, they touch and support each other. This creates a state of resistance against the flanges that meet each other. The reason for this is that the flanged body impedance to movement of one or both of the parts, or the inherent strain or strain of the flange. is either in the irregularities or in the gasket or seal member between the flanges. However However, this type of known bolt installation procedure is characterized by the following points. i.e. bolt By controlling direct stress generation, the nut is held in place with minimal torque. It is screwed into place, but as it does so, it slides along the prestressed joint bolt. The nut is screwed in with low torque, until there is actually resistance from the flange. Although it is screwed in, a situation arises where it is mistakenly thought to have occupied the correct position. Pol l - When the hydraulic pressure of the stress generator is released, the flanges of the body part should be properly connected to each other. The expected residual stresses in the bolts will compress the flanges if they are not joined to rather than disappearing due to subsequent movement of the flange.

These situations require significant levels of torque to be applied to the nut and the required flange displacement. This could be solved either by creating a problem or by using a hydraulic bolt tightening device.

In the case of this hydraulic bolt tightening device, the tensile stress is induced by the reaction of the flange. .

By using a fairly high torque value for tightening the nut, the drawbacks of conventional nut tightening are avoided. Certainty points seem to arise again. On the other hand, it causes a reaction to the body. The said bolt tightening device has the problem of obstructing the accessibility of the nut and/or or the problem of requiring more air space than is available between closely spaced bolts. , and/or the risk of localized damage to the body that reacts to the tensile forces. I have a problem that there is.

Furthermore, in both the procedures outlined above and the possible procedures, a large number of closely spaced Connection of two flanged bodies such as turbine casings with joint bolts There is little scope for speeding up and/or automating the process.

The object of the present invention is to provide a method for compression joining two body parts having holes in a face-to-face state. The present invention aims to provide a welding device in which the drawbacks of known devices are alleviated and which can be automated to a large extent. Ru.

According to a first aspect of the invention, a plurality of connection bolts (as defined herein) The method of facing two body parts having twisted holes and compressingly joining them is as follows. have. In other words, (1) a plurality of holes are connected to each other as pairs of holes spaced apart from each other; (2) at least two bolts, with the body parts facing each other; At least one of the connecting bolts passes through the adjacent pair, thereby connecting each bolt. The head end of the bolt abuts one body part and the threaded shank rests against the other body part. (3) Place a nut and a hydraulic stress generator on the joint bolt. (4) At least one of the adjacent bolts Assemble a hydraulic nut onto the protruding shaft end of the bolt, with a portion of the nut protruding from the protruding shaft. One part is engaged with the shank end and another part is supported by the protruding body part of the bolt. (5) applying hydraulic pressure to the hydraulic nut and the hydraulic stress generator of the bolt; The resulting expansion of the hydraulic nut forces the body parts into contact with each other. and a predetermined installation in the joint hole/U) by extension of the hydraulic stress generator. (6) occupies a desired position relative to the stressed shaft; (7) Apply hydraulic pressure from the hydraulic nut and the hydraulic stress generator. unlock.

According to a second aspect of the invention, a plurality of through holes in the form of mutually aligned hole pairs A joining device for joining two body parts having the following features: sand (1) Hydraulic pressure source. (2) Hydraulic nut device. This device can be used from one of six pairs of holes. It can be operated to apply tensile stress to the protruding bolt shaft, and this tensile stress can be The force acts against the body part that has the hole, thereby causing the other body part to Both body parts are pulled into contact with each other through the bolt head that is in contact with the I can't stand it. (3) Hydraulic stress generator (of a defined type). This device has an internal Connection bolts (of a defined type) that protrude from six adjacent pairs in response to hydraulic pressure. Apply a tensile stress to the shank of the bolt that reacts to the opposite end of the bolt. (4) Hydraulic stress Nut rotating device combined with generator. This device allows the joining bolts to connect with each other. The bolt that is in contact with one body part is so that the nut is held through the head of the nut and the nut is held on the shaft of the other body part. It is operable to be positioned relative to the minute. (5) Control device. This control device The positions are operable to cause the next action in sequence. (a) Said hydraulic nut both the device and the hydraulic stress generating device by means of its hydraulic pressure against said adjacent bolt. actuated to create a predetermined level of tensile stress within the joint bolt. (bl nut rotation Operation of the device. (C) Due to the stoppage of operation of the hydraulic nut device and the hydraulic stress generating device. , a predetermined level of residual stress is created in the joint bolt through the joint bolt head and the nut. Ensure that at least similar values are achieved.

Embodiments of the invention will now be described with reference to the accompanying drawings: FIG. FIG. correspondence in which two parts of the body have six aligned pairs The flanges are joined together by compressing them facing each other with joining bolts. figure shows the distribution of holes in the flange and the proximity of the connecting bolts.

FIG. 2 is a schematic illustration of the joining device according to the invention, in particular the joining of two adjacent flange holes. By the way, this shows the joining work.

Figure 3 shows a series of operations related to the initial installation of the joint bolts in Figures 1 and 2, and FIG. 2 is a process flow chart showing subsequent monitor work and correction procedures.

The body lO1 shown in FIG. 1, for example a turbine casing, has two corresponding bodies. Part 10. ．． 10. The peripheral flange eyes + and 112 face each other, respectively. It is formed by being compressed and held in compression. This compression occurs at the periphery of the body. carried out and maintained. That is, along the flanges, The joint bolts 13 are passed through the holes, and these bolts 13 are Tensile stress is applied by the bolt head 14 and nut 15 pressing the opposite flange. maintained in the condition it was acquired.

In many other cases similar to this application, the flange is The compressor is compressed at symmetrically located locations around the casing to prevent damage. is preferred. This is especially true if the flanges are not in their natural facing position for some reason. If not, in other words, there is a resistance to uniform precompression, and Therefore, casing distortion that is joined only at one or more distant points is promoted. This applies in such cases.

Even if this consideration is given to evenly distributing flange compression, the number of adjacent holes and Proximity actually limits the type of joining bolt.

Also, the problem mentioned above, i.e. where there is no natural mutual contact of the flanges, The problem involved in obtaining a constant Porto residual stress within fixed limits is that some form of polymorphism It is possible to consider each joint bolt separately from the joints at several locations.

Figure 2 shows small parts of the flanges Ill and +12 of the body. Ru. Although the flanges are shown in face-to-face relationship, they are separated by a slight gap.

For clarity, only the main parts are shown in the figure. This gap is for the flange This is due to the inherent reluctance or because contact is not possible at all locations. .

Alternatively, this may be due to the placement of sealing or gasketing material.

This material requires a certain amount of force to be deformed or compressed, but It is not of the same magnitude as the magnitude of the force ultimately applied by the joining bolt. .

The flanges each have through holes 17, 18, these holes are shaped like the body. , and each of these hole pairs will be referred to below as a hole pair. ” I will call it 191.+92.

The connecting bolt 13 (predefined) extends through the six pairs 191 and connects another pole 191. −21, also preferably with the joining bolt shown as the immediate hole pair +9t It extends through six adjacent pairs.

The joint bolt/leaf 13 has a shaft portion 22 with an external thread, and a nut is attached to one end 221 of the shaft portion. It has a hole 23. The nut 23 forms a head 14 at the end of the shaft. It is effective to do so. The shaft also has one end 22+ and the other end 22. vertical axis between A void 25 exists along the line. For convenience, the shaft has a cavity 25 extending between both ends. The plug 26 is formed as a through hole, and the through hole is closed with a plug 26. .

The outer surface of the shaft portion 22 is provided with a conventional thread at least toward the end portion 22□. can be engaged with the nut 15, and the cross-section 5 is screwed in along the shaft part. be able to. Therefore, the connecting bolt 13 is connected between the flanges 11+ and +14. A compressive force is applied to the flange through the nut and the head, which creates a tensile force inside the shaft. Maintain stress.

The connecting bolt 13 and the bolt 21 are considered to be part of the body, and are Then the joining device according to the invention is activated.

The joining device, generally designated 29, has five main components.

That is, the hydraulic pressure source 30, the hydraulic nut device 40, the hydraulic stress generator 50, the They are a rotating device 60 and a control device 70. These devices are described below.

The hydraulic source 30 is powered by compressed air from an air source (not shown) via an air control valve 32. It has a hydraulic pump 31 which is driven by the hydraulic pump 31. The air control valve 32 controls the operation of the pump 31. The cropping time is determined, and this timing is controlled by a control device 70. Hydraulic circuit is a liquid It has a return control valve 33 which determines the pressure in the feed line 34. this line 3 4 is monitored by a pressure drainer 35. This transition The output signal of the regulator 35 is sent to the control device 70, and the control device 70 controls the return control valve 3. 3 or the state of the air control valve to create or maintain a constant flow rate or pressure. let A pressure source combined with a controller is set at a high flow rate to deliver low pressure fluid. Furthermore, the control pressure can be increased while continuing discharge at the same low flow rate.

Hydraulic nut arrangement 40 includes a hydraulic nut 41 of conventional type. Natsu 41 is It has a first annular portion or nut body 42 . The nut body 42 is a screw of the bolt 21. It has an internal thread that engages with the cut shaft, and also receives hydraulic fluid from the hydraulic pressure source 30. It has an annular recess 43 forming a cylinder. The nut 41 further includes a second It has an annulus or load ring 44 which responds to the hydraulic pressure within the recess 43. to form a piston that can reciprocate within the recess relative to the shaft and press the flange lit. do. The force splitting between the two nut parts pushes the bolt head towards the nut, and At the same time, the other flange 11. results from the pressure that moves it adjacent to 2 The two flanges are brought into close contact. shaped by the supply liquid pressure and the second portion 44. The relationship between the cross-sectional area of the piston and the cross-sectional area of the piston is as follows: sufficient to cause the screws to contact each other, but not enough to cause damage or distortion. Furthermore, the tensile stress generated within the bolt is sufficient to cause permanent deformation of the bolt. The relationship is as follows.

The hydraulic stress generator 50 has a hydraulic stress generator combined with the connecting bolt 13. ing. This stress generator has an actuating rod 51. The actuating rod 51 is The plug 26 at the end 221 of the bolt head and the other end 22 . Operation head 5 beyond It extends along the space 25 between 2 and 2. The operation head 52 includes a cylinder body 54. A piston 53 is provided that can reciprocate within. The wall of the cylinder body 54 is extending beyond the shaft and having a thread at 55, the threaded end of the shank 222 and is retained thereby. piston and cylinder The body forms a liquid chamber 5G, and the operating head is assembled on the shaft as shown in the figure. Then, the actuating rod 5I extends into the cylinder body toward the piston, thereby providing Hydraulic fluid is supplied from the hydraulic pressure source 30 to the liquid chamber 56 via the supply line 57 and the coupling 58. Sent. Two hydraulic pressures force the piston and cylinder body in opposite directions. separated by the force applied to said opposite ends 21+, 222 of the connecting bolts, respectively. tensile stress is applied to the joint bolt.

The hydraulic pressure supply line 57 is connected to the hydraulic pressure source 30 at 34, so that the operation The actuation applied to the operating head is equal to the hydraulic pressure applied to the adjacent hydraulic nut 41. but, Since the piston area on which hydraulic pressure acts is larger than the area of the hydraulic nut 41, the joint bolt The tensile stress applied to the bolt 13 is greater than the tensile stress applied to the bolt 21. .

The nut rotation device 60 has a nut rotation motor 61 for the joint bolt I3. . Preferably, this motor 61 is held by the operating head. drive The gear 62 is held on the motor shaft or at least rotates with the motor shaft. I'll keep it that way. In addition, the corresponding driven gear ring 63 is integrally formed with the nut I5. Either make it the same or attach it in a removable manner. The nut rotating device is further , has a preload ram 64. This ram 64 is attached to one pole of the adjacent bolt 21. It is preferable to attach it removably, and also apply a preload to the head 23 of the joint bolt 13. and is operated so as to come into contact with flange II+. The nut rotating motor is Control device 70 provides control over the effecting of the position change. motor 6 I is preferably a stepper motor with a number of steps depending on the desired nut rotation. It is possible to change the nut position simply by using a sobbing pulse, or Alternatively, a conventional continuous circuit with a position sensor and forming part of a servo control loop may also be used. A rotatable motor may also be used. The model of the motor and how the position changes. Nevertheless, the motor 61 is configured to produce only a relatively low l-lux. Ru.

This low torque, unless otherwise suppressed, is sufficient to rotate the nut. It is possible, but the oak l- is flange 11. If it comes into contact with the There are no words that can generate a degree of axial force. This is the power supply to the motor or These power limits are the result of inherent power limits on the motor itself, and these power limits can prevent the motor from stalling. make it come alive. Alternatively, it can sense the load on the motor and follow a predetermined value. This results from limiting the output.

The control device 70 has a central control unit 71 . The unit 71 is the hydraulic pressure source 3 0 and the nut rotating device 60. This control creates residual stress in the flange. The predetermined work sequence for attaching the joining bolts, and the The actual value of the residual stress in the bolt is the value ostensibly obtained by this given sequence of operations. A signal from transducer 72 measures the actual value if it differs from and another predetermined procedure to be determined.

Control unit 71 is preferably implemented by a microprocessor. This my The processor is configured to perform tasks that are desired to be performed according to the second aspect of the invention. Accordingly, some conventional format is programmed accordingly.

First, connect the flanges 11+ and IIs near the adjacent hole pair 191 and 192 with the connecting bolt 1. 3 and bolt 21 will be considered. As mentioned above, Bolt 21 Preferably it is a joint bolt.

Flange I1. ．． The IL is aligned with respect to the through hole, but the gap 16 is They are spaced as shown. Bolts 13.21 each have an adjacent hole pair 19 +, l is inserted into 9t. The hydraulic nut 41 is assembled on the shaft of the bolt 21. As a result, the bolt head contacts the flange 11+, and the hydraulic nut 41 contacts the flange 11+. Contact lunge IL.

The nut 15 is screwed onto the shaft 22 of the bolt 13, and then the hydraulic stress generator is Can be assembled. The actuating rod 51 is arranged in the bolt cavity 25 and is connected to the operating head 5 2 screwed into the end of the shaft. Next, the nut rotating device 60 is assembled and the motor 61 is in driving connection with the nut via gears 62, 63 and also with the connecting bolt 2. The head of the bolt 13 is connected to the preload ram 64 attached to one head, and the head of the bolt 13 is connected to the flange. Pressed against 11+.

The motor 61 is connected to a control unit 71 and receives an appropriate drive signal from the control unit 71. The signal is received via line 73. The operating head 52 and the hydraulic nut 41 are It is hydraulically connected to a common output line 34 of the pumps 31.

The data stored in the control unit 71 is the residual stress target value of the joint bolt.

This target value is a target value in the case of mutual meshing with the nut 15. Considering these points In view of this, the control unit 71 determines whether the nut occupies a position where a predetermined residual stress is achieved. Indicate the initial tensile stress or installation tensile stress that must be applied to the joint bolt so that the or can be calculated. This mounting residual stress, of course, The force exerted between the rod 52 and the actuating rod 51 directly causes the liquid to It is related to the hydraulic pressure within chamber 56. Therefore, the control unit 71 actually The hydraulic pressure value is memorized and this hydraulic pressure value is used instead of the initial tensile stress and/or residual stress value. , or in addition to that value, gives the installation tensile stress for a specific bolt. .

FIG. 3 shows connections carried out by or under the control of control unit 71. Each treatment method is summarized.

The control unit 71 operates the hydraulic pressure source 3o and causes the fluid to flow through the line 34 at an appropriate pressure. is discharged, and the head 52 and hydraulic nut 41 are operated.

Fluid pressure acts within the hydraulic nut 41 to separate the two portions 42 and 44. , the bolt head is in contact with flange II+, and the nut part 44 is in contact with flange IL. Force contact. At the same time, fluid pressure acts within the operating head 52 to A predetermined tensile stress is created between both ends of the nut 13, and the ram 64 of the nut rotating device is A preload is applied to bring the head of the joining bolt into contact with the flange 11+. after a few seconds Both flanges are pulled together by the hydraulic nut 41 and attached to the joint bolt 13. The control unit then stretches by applying a tensile stress, and the maintained pressure causes the control unit to further The nut rotating device 60 is excited, and the motor 61 rotates the nut 15 along the shaft. , in contact with the flange Ilz. The load on the motor is detected and the supply to the motor is The stalled motor may easily be de-energized after the power is removed or after a suitable interval. I can't stand it. Following this, hydraulic pressure is removed from the hydraulic nut 41 and the head 52 is operated. be done. The tensile stress applied to the joint bolt can be calculated from the installation stress value by the nut 15. Only slightly lower residual stress levels are maintained as long as possible.

The flange is therefore probably in place, at least at this point. held in compression by the force of Next, the nut rotating device, the operating head, Hydraulic Nara) is removed. If desired, the operating head and nut rotating device can be It may be assembled on the bolt 21 next to the nut (not shown) corresponding to nut 5. stomach.

The bolt is secured in a similar manner, but without or adjacent to the hydraulic nut. A hydraulic nut is moved up to a bolt that extends through a connecting socket (not shown). More fixed.

If it is assumed that the predetermined residual stress is not generated in the bolt 13 with sufficient accuracy, Preferably, the hydraulic stress generating device, nut rotating device, and hydraulic nut should be operated before removal. Another control sequence for the operation is transmitted via the controller to the transducer 72. This is done in response to the measurement of the actual value of the residual stress of the joint pole [3] according to No.

The control device is simply analogous to the associated initial tensile stress as described above. It is required to memorize a predetermined or target value of residual stress rather than fluid pressure; Determine the actual value of the residual tensile stress directly or indirectly from the signal of the transducer 72. and compare this value with the target value to check the error value. Small error indicates acceptable tolerance If the threshold value is exceeded, the control will activate the nut rotation to change the residual stress in the bolt. Calculate the displacement or look it up from a table to eliminate measurement errors. increase residual stress If necessary, the bolt should be stretched sufficiently by applying additional tensile stress to the bolt. It is clearly required that the bolt must be moved further towards the bolt head. On the other hand, If residual stress must be reduced, move the nut away from the bolt head. However, there is a clear need to reduce the residual load from the nut. Therefore, the required The sign and magnitude of the nut rotation caused can be determined directly or by this modified tensile response. Force/required bolt extension, measured via the minimum hydraulic pressure required by the operating head. Used for calculation or key.

Once all these values have been verified, the control unit operates the hydraulic pressure source to The pump 31 delivers fluid to the hydraulic nut 41 and the operating head 51 until the determined pressure is achieved. , thereby achieving the determined modified tensile stress. The joint bo/U) is under this modified tension. Once the stress is considered to be elongating, the controller operates the nut rotating device to tighten the nut. The joint bolt head 23 is connected to the flange 11. so that a preload is applied to the motor 61 is operated so that nut 15 is repositioned by a determined amount.

The controller 71 then causes pressure to be relieved from the hydraulic nut and the hydraulic stress generator. Make it.

At this stage, if this one-time modification is deemed appropriate, or alternatively Re-measure and repeat the above procedure until no errors are found that should be removed. , the nut rotation device and the hydraulic nut 41 are removed from the bolt 13.21 and replaced with another bolt. Repeat all the above steps for each target.

The initial installation described above is based on the procedure or sequence and the actual conditions rather than the predetermined conditions. a flanged body joining method indicated by an alternative procedure or sequence that In the case of joint bolts that must be maintained at It is separate from the force applied to the nut which needs to be positioned above. Bol When positioning the nut on the bolt, what is the force that acts between the nut and the bolt shaft? There is no need to overcome another force. The device used for this positioning is assembled once. If the Follow-up work to achieve predetermined values through iterative corrections should be carried out. I can do it.

As mentioned above in connection with Figure 1, flanged bodies such as turbine casings The body 10 has multiple hole pairs and also actually has several separate holes on the body. joining the flanges simultaneously in place and preferably with the shortest possible assembly time; Multiple joint bolts must be installed simultaneously at each location.

The joining device according to the present invention is suitable for such work. Looking at Figure 2 again, The hydraulic source 30 includes a liquid distribution manifold 36 in the pump discharge line 34. ing. This manifold 36 has a plurality (six in the illustrated case) of hydraulic nuts and and the operating head pair. In other words, the hydraulic Nara 1-device 40 has the symbol 41, each hydraulic stress generating device 50 has six hydraulic nuts corresponding to Six hydraulic stress generators having working heads 52 and working lots 51 are provided.

Therefore, the nut rotating device 60 has six motors 61 and a preload ram 64. Ru.

Similarly, the controller 70 includes a transducer multiplexer 74. are doing. This device 74 is operated by each of the joint bolts installed at the same time. Signals from multiple transducers 72 held can be received. By this the transducer signal is received by the control unit 71, or It is also sampled from each bolt and applied to each bolt again.

The nut rotation demultiplexing device 75 also repositions the nut of each bolt. The nut rotation signal that is emitted when the rotation is It can be distributed to each bolt associated with the transducer.

During work, when installing 6 joint bolts in 1 group, the control unit will Poll the transducer and, if necessary, the required amount for each of the six bolts. Determine the Nando position correction value to achieve the maximum required correction tensile stress value. control equipment The system operates a hydraulic pressure source and distributes that pressure through manifold 36 to all operating heads. and adjacent hydraulic nuts, and then sequentially associated with six bolts. y start the determined repositioning.

The exact number of joint bolts in one group or the placement of bolts on the body flange is Various selections are possible. However, in that case, a very large Multiple joint bolts may be used when each bolt must maintain a high compressive force. Install every other hole pair in a series together in one location, and also have hydraulic Make sure that the bolt that holds the bolt touches it. If possible, install it throughout the body. All six pairs are treated as a single group. shall have a bolt holding either a joint bolt stress generator or a hydraulic nut. This results in stress being applied to all bolts simultaneously.

Depending on the number and proximity of holes, the magnitude and distribution of flange compression force, flange behavior, etc. , different installation formats can be adopted. In particular, a series of joint bolts in one place When installing bolts, space the bolts wider than every other hole, but avoid uneven spacing. Make sure to install it with the For example, each joint bolt holds a hydraulic nut 41. This means that a pair of mating bolts A bolt with a hydraulic nut 4I is placed between the bolts, and the two adjacent pairs are joined together. Make sure you understand that bolts match and vice versa.

Depending on the circumstances, the configuration of the flanges and the force required to bring them into contact with each other The installation of the bolt is performed by simultaneously applying stress to the joint bolt 13 and the liquid. It is possible to do this with a pair of holes that hold the pressure nut and the I leaf 21 and force are passed through, if or even desirable. These six pairs are close together but not adjacent. Paraphrase are located closest to each other, sufficiently close together, and the structure and behavior of said flanges Regarding movement, the flange can be tightened using hydraulic nuts as effectively as in the case of six adjacent pairs. is possible.

If the flanged body parts are particularly spaced apart (due to gaps 16), and/or installations in a small number of well-spaced locations may be initially tightened together. If deformation is likely to occur in the vicinity of each joint bolt to be installed, It is desirable that the flange clamping force be distributed more evenly Yes. i.e. several additional bolts holding hydraulic nuts, such as bolts 21. Tighten the flange over a flange area that is larger than the adjacent area of the connection bolt using Try to attach it.

The control device 70 includes devices related to installation, which are controlled by the central processing unit. It is most convenient to control. For example, residual tensile stress measurements or correction pressures. The determined correction values and intermediate values are recorded for each volt and displayed on the display unit 76 and/or Alternatively, the data can be viewed using the printer 77, and data can be entered using the keyboard 78. It is Noh. In addition, the control device stores a memorized location used for the initial installation of the bolt group. Depending on the determined error, the attachments used for subsequent bolt groups converge to the value. make it possible to do so. These installation values may be modified with a few further correction procedures or is the value that satisfies the tolerance without any correction procedure.

Transducer 72 includes an ultrasound device. From this device, both ends of the bolt The tensile stress of the joint bolt, which is related to the length between emits a signal indicating the This transducer is fitted with a suitable acoustic coupling and acoustic reaction. It is necessary to add it to a position where the radiation can be received correctly. This transducer is Also, it can be used together with a commercially available tensile stress measurement device 80 or as a part of this device 80. You can stay there. This device 80 is an oscilloscope that assists in place of a transducer. is combined with the This device 80 has each transducer according to the multiplex communication method. connected to control unit y h 71 for locating the It also allows you to visualize each measured tensile stress in real time during the installation. and/or perform some of the calculations for each stress value from the transducer. It is preferable that the

Many individual items or items need not take a form exactly equivalent to the above description. stomach. In addition, what has been said in appropriate parts of the above description and within the scope of the prior art, do not have to take exactly the same form. The type of pressure source or hydraulic nut device, or The type of hydraulic stress generator can also be used to the extent that the above-mentioned functional effects can be achieved. , may be in another modified format.

The nut rotating device 60 is a ram device for arranging the head of the joining bolt adjacent to the flange. It has a position 64. This ram device 64 can be used to remove objects outside the headboard of adjacent bolts, e.g. Depending on the nature of the bolts, other parts of the flanged body or even on a suitable floor is supported regardless.

Furthermore, the nut rotating device associated with the control device can also be modified from the type described.

In the type described, the nut position is determined upon initial installation of the connection bolt.

If a given level of tensile stress is present in the bolt shank, the initial installation will be It is preferable to position the nut so that it makes contact with the flange at this point. The position is independent of the initial Nand position, simply rotate the nut to make contact with the flange. This can be easily achieved by touching the However, the nut of each joint bolt is in a known position, i.e. in contact with some marker on the operating head or shank. If the nut is placed in the The nut position is corrected by displacing the nut by a certain distance according to the tension stress.

The type of hydraulic stress generator may also vary depending on the design of the connecting bolt. for example If the operating head has a central cavity that opens towards the end of the head, the connecting bolt Attached to the head or effective head, or attached to the outside of the head so that it is installed on the In such cases, a hydraulic stress generator may be inserted into the hole pair. It is desirable or appropriate to assemble on the bolt that precedes the bolt that is Additionally, installation tensile stress can be applied to the bolts before inserting them into the six pairs. , this allows smaller holes to be used and reduces radial interference due to residual stresses. Fit is possible.

The method and apparatus for joining body parts together, as described above, is It can be used for closed bodies such as It can also be used on other bodies. In that case, the precision inside the joint bolt In addition to uniform residual stress settings, measures are taken to facilitate contact between flanges. will be developed. Further, the method and apparatus of the present invention are not limited to joining flanges of bodies. It has six pairs aligned and compressed by similar connecting bolts. Can be applied to mating body parts that are joined in the situation.

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1++++++ll+j++++++ PCT/GB 93101010 International Research Report notice

Claims (1)

[Claims] 1. The two body parts (111, 112) having holes face each other, and at least In a method of joining in a compressed state using one self-stress-generating joining bolt (13) , (i) The body parts are arranged facing each other, and the plurality of holes (17, 18) are spaced apart from each other. (ii) at least At least two bolts (13, 21), one of which is a joint bolt, are inserted into adjacent hole pairs ( 191, 192), each bolt head (14) of each bolt is Adjacent to one body portion (111), a threaded shank (221) is located on the other side. extending from the body portion (112) to each protruding shaft portion (222), (iii) nut (15) and hydraulic stress generator (50) on the joint bolt (13); Assemble the (iv) a hydraulic nut on each of said protrusions of at least one adjacently disposed bolt; (41) is assembled, a part of this nut (41) engages with each of the protruding parts, and the other part part rests on the protruding body part (112) of the bolt, (v ) both the hydraulic nut (41) and the bolt hydraulic stress generator (50); Applying hydraulic pressure from a hydraulic pressure source (30) to the hydraulic nut, the body is The two parts are forced into contact with each other and are brought into contact by extension of the hydraulic stress generator. A predetermined attachment tensile stress is generated in the joint bolt (13), and (vi) the joint bolt Rotate the nut (51) on the shaft so that the nut (51) (vii) Hydraulic nut (41) and hydraulic nut (41) having a hole, characterized in that it releases hydraulic pressure from both sides of the stress generator (50). A method of joining two body parts. 2. A method according to claim 1, in which each bolt (41) holding a hydraulic nut (41) 21) has less than each bolt (13) holding the hydraulic stress generator (50). A method characterized in that stress is applied to a certain degree. 3. 3. The method of claim 1 or 2, wherein (i) a tensile stress is applied to the nut (15). ) for at least one joint bolt (13) maintained by this bolt determining at least a representative value of the residual tensile stress of (72); (ii) To generate the residual stress target value from the error between the determined value and the target value. Determine an appropriate amount of change in the nut position relative to the bolt (71), (iii) A hydraulic stress generator (50) on each of the joint bolts (13) and the adjacent bolt (13) 21) Apply hydraulic pressure (30) to both the hydraulic nut device (40) above, thereby to fully extend each of the joint bolts, and the nuts (15) are set according to the determined values. while the contact force between the body parts adjacent to the nut is maintained. So, (iv) reposition each nut (15) according to the determined amount of change; (v) One characterized by releasing the hydraulic pressure from both the pressure nut and the hydraulic stress generator. Law. 4. The method according to any one of claims 1 to 3, wherein among the plurality of adjacent hole pairs, Hydraulic stress generator for multiple joint bolts (13) extending through alternate holes of (50) A method characterized by simultaneously applying tensile stress. 5. The method according to claim 4, when dependent on claim 3, For each of the multiple joint bolts holding the raw device, the representative of the residual stress and also all of the plurality of joint bolts (13) and their adjacent bolts. (21) and a hydraulic stress generator (50) and a hydraulic nut device (40). A method characterized in that applying (30) hydraulic pressure to. 6. A method according to any one of claims 1 to 5, in which each joint bolt (13 ) and the associated nut (15) are rotated by a motor (61) connected to the nut. A method characterized in that it is carried out by 7. A method as claimed in claim 6, when dependent on claim 3, in which the plurality of connections The motor (61) involved in repositioning the nut (15) of the mating bolt (13) is A common control device (70) determines the time division multiplexing (ti according to the amount of change distributed by memultiplexing (74, 75). A method characterized by sequential operations. 8. A plurality of through holes (17, 18) are aligned with each other as a hole pair (191, 192). In a device for joining two body parts (111, 112) that are i) a hydraulic pressure source (30) is provided; (ii) the hydraulic nut device (40) extends from one hole (18) of the hole pair (192); The body part (112) having a hole is attached to the shaft part (22) of the bolt (21) that extends. can be manipulated to apply a counteracting tensile stress to the other body, thereby The two bodies are pulled together and in contact by the bolt head adjacent to part (111). forced, (iii) The hydraulic stress generator (50) responds to the internal hydraulic pressure to The opposite side to the shaft (22) of the joint bolt (13) protruding from (191) (iv) generate hydraulic stress by applying a reactionary tensile stress to the bolt head (14) The connecting bolt (13) connects the nut rotating device (60) associated with the device (50). Both connections are made through the bolt head (14) which is in contact with the other body part (111). It can be operated so that it is held against the body part that is being touched, Furthermore, the nut rotating device (60) is arranged so that the nut (15) on the shaft part is connected to the other body. operable to be positioned relative to the portion (112); (v) The control device (70) can be operated sequentially as follows: (a) Attach the hydraulic nut device (40) and the hydraulic stress generator to the adjacent bolt. On the other hand, it is operated with a hydraulic pressure that causes the tensile stress in the joint bolt to reach a predetermined level. , (b) actuating the nut rotating device (60); and (c) operating the hydraulic nut device (60); 40) and the hydraulic stress generator (50) are stopped, and the connecting bolt head and nut are removed. Achieving a value that at least approximates the predetermined level of residual stress in the joint bolt through A device for joining two body parts, characterized in that it is operable to . 9. The joining device according to claim 8, wherein the control device (70) is configured to Determine the tensile stress installation level for the joint bolt (13) and the corresponding hydraulic pressure value. Also, the nut rotating device (60) rotates the nut (15) onto the shaft portion. and is configured to be displaced until it comes into contact with the other body portion (112). A joining device characterized by: 10. Apparatus according to claim 8 or 9, characterized in that the stress transducer (72) , can be operated so as to obtain a representative signal of the residual tensile stress of the joint bolt (13). the controller (70) further responds to (i) the transducer (72) to Displacement of the nut (15) required to eliminate the difference between the target value and the actual value of the retention tensile stress (ii) operable to calculate the modified tensile stress for the connection bolt; and this joint bolt is free to move the nut in order to cause said displacement. and (iii) operable to cause the next action in sequence. Yes, that is, (a) the hydraulic nut device (60) and the hydraulic stress generator (50) , with respect to the joint bolt (13) and the adjacent bolt (21). (b) the nut rotating device (60) is actuated with hydraulic pressure capable of imparting a modified tensile stress; (c) said hydraulic nut device and hydraulic pressure; A joining device characterized in that it is operable to stop operation with a stress generating device. Place. 11. The joining device according to any one of claims 8 to 10, wherein the hydraulic pressure source (3 0) supplies hydraulic fluid at a predetermined pressure at a predetermined time by a control device (70). A bonding device configured to discharge. 12. The joining device according to any one of claims 8 to 11, wherein the nut rotation A device (60) has a motor (61) connected to a nut (15) and a bolt shaft. The nut can be rotated around (22), and the nut position can also be changed. A joining device characterized in that the position can be controlled to be determined. 13. The joining device according to any one of claims 8 to 12, wherein the nut rotation The device (60) has a ram device (64), which is connected to the joining bolt head. (14) is operable to apply preload to bring it into contact with the body part. A joining device for 14. The joining device according to any one of claims 8 to 13, The spring device (80) is individually connected to the plurality of joint springs (13) extending through the plurality of hole pairs. a plurality of hydraulic link type hydraulic stress generators (52) adapted to Further, the hydraulic nut device (40) includes a plurality of bolts (21) extending through the plurality of hole pairs. ) with multiple hydraulic link hydraulic nuts (41) adapted to be individually associated with each other. and, as a result, adjacent joint nuts each holding said stress generator A joining device characterized by being located within a region. 15. In the joining device according to claim 14, when dependent on claim 10, The control device (70) has a multiplexing device (74), which device (74) in turn from the stress transducer device (72) associated with each joint bolt. the controller (70) is operable to receive a demultiplex signal; The device (75) is adapted to respond to the detected residual tensile stress value. be operable to actuate the nut rotation device for the corresponding joining bolt. Characteristic joining device.