JPH0363002B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an operation detection device for a swash plate compressor, and more particularly to an improvement in a detected portion that is a counterpart to an electromagnetic sensor that emits a voltage pulse signal by electromagnetic induction.

To detect the operating status of a machine, such as whether it is running or stopped, operating speed, etc.
Conventionally, an electromagnetic sensor is disposed so as to face a part of the periodic motion locus of a detected part that performs periodic motion in relation to the motion of the machine, and the electromagnetic sensor is configured to obtain a pulse signal. Although it has been proposed,
If a member of the machine that performs periodic motion is made of a non-magnetic material such as an aluminum alloy, an appropriately sized detection portion made of a magnetic material such as a ferrous metal may be adhered or embedded on its surface. It is being implemented. Regarding the above-mentioned burial, there are two methods: press-fitting, and the first method.
As shown in Fig. 2, one possible method is to fit the detected part 103 into a hole 102 drilled on the surface of the moving member 101 and fix it with an adhesive 104, but in the former case, the base material made of light metal may be deformed. If the detected part is made of a brittle material such as sintered material, problems such as breakage may occur, and in the latter case, the detected part 103
Air may remain trapped behind the back of the unit, and if it is used as is, the trapped air may may expand and push out the detected part 103, or the adhesive may peel off due to various forces and heat applied with long periodic motion and the detected part may fall off and come into contact with other parts of the machine. Not only is there a risk of the device falling off and causing an accident, but it also loses its function as a detection device. In addition, in a swash plate compressor, the shoe is pressed under high pressure due to compression reaction force and moves at high speed with the swash plate, so there is a risk that the shoe and swash plate may seize due to insufficient lubrication. In particular, when used in vehicles, there was a risk of serious accidents.

In view of this, the present invention provides a swash plate type compressor in which a fluid containing a magnetic material in the form of particles (powder) and a binder is applied to a recess formed on the surface of a member made of a non-magnetic material that performs periodic motion. The object of the present invention is to provide an operation detection device that can eliminate the above-mentioned drawbacks by filling and fixing the liquid into the hole to almost the same height as the opening of the recessed hole and using it as the detection area. Ta. First, regarding the configuration of the detected part of the present invention,
A detailed explanation will be given below based on the illustrated embodiment.

In FIG. 1 and FIGS. 3 to 5, reference numeral 1 indicates a rotating member (for example,
A detected portion 3 is embedded in the outer peripheral surface of the rotating member 1 (swash plate). The detected portion 3 is configured to apply a liquid containing a mixture of magnetic material particles 6 and a bonding agent to the outer circumferential surface of the concave hole at an opening position in a concave hole 4 formed in the outer circumferential surface of the rotating member 1. It is formed by pouring to the same height and filling and fixing. At this time, temperature-sensitive ferrite is used as the magnetic material particles 6, and thermosetting resins such as phenol resins and epoxy resins can be suitably used as the bonding agent 5. In addition, by solidifying the binding agent 5, the magnetic material particles 6 are fixed in their mutual positional relationship, and
No matter what shape the inner circumferential wall of the recessed hole part 4 has, it is tightly fixed without any gaps. However, in order to reliably prevent the detected part 3 from falling off even if separation occurs between it and the inner circumferential wall of the recessed hole part 4, the following measures have been taken. That is,
In FIG. 3, a partially conical bulging portion 4a is formed in the inner part of the side wall of the recessed hole portion 4, and the cross-sectional area of this portion perpendicular to the exit direction is larger than the opening area of the recessed hole portion 4. In FIG. 4, an annular bulge 4b with a rectangular cross section is formed in the middle of the side wall of the recessed hole 4 to achieve the same effect. In addition, in FIG. 5, the side wall of the recessed hole 4 itself has a partially conical bulge 4 that widens inward.
It is shown that it is formed as c and exhibits a similar effect. Further, the portions of the detected portions 3 exposed on the outer surface are finished by polishing or the like after consolidation so that they are flush with the entire outer circumferential surface of the rotating member 1. An electromagnetic sensor 7 is attached to a fixed member 8 so as to face a part of the periodic motion locus of the detected part 3. A bar-shaped magnet 9 directly facing a part of the periodic motion locus, a coil 11 surrounding the side surface of the magnet 9 and having an output terminal connected to an external control device via a lead wire 10, and these magnets 9 and the coil 11. and a main body part 12 for fixing and holding the parts.

In the device of the present invention configured in this way, when the machine is in operation and the rotating member 1 rotates, the detected portion 3 periodically faces the end face of the electromagnetic sensor 7 and eventually the magnet 9; Even if the detected part 3 is a collection of particles, it is ultimately made of a magnetic material.
When approaching and separating from the magnet 9, the magnetic flux density of the magnet 9 is changed, and an electromotive force is generated in the coil 11 based on this, and the coil 11
A pulse signal of a voltage as shown in FIG. 10 is obtained at the output terminal of. Based on the pulse signal obtained in this way, the external control device connected via the lead wire 10 determines the operation/stop status of the machine depending on the operating speed of the machine and the presence or absence of the pulse signal. Can be detected.

Next, an example in which the present invention is applied to a swash plate compressor suitable for vehicle air conditioning will be described with reference to FIGS. 6 to 11. 15 and 16 are front and rear cylinder blocks facing each other, and both ends of these cylinder blocks 15 and 16 are closed by front and rear housings 18 and 19 with valve plates 17 and 17 interposed therebetween. There is. A drive shaft 20 extends through the axial center of the cylinder blocks 15, 16, and one end thereof protrudes through the front housing 18 so that it can be connected to an external drive source. Note that the protruding portion is kept airtight by a shaft sealing device 21. A suitable number of pairs of cylinder bores 22, 22 are bored in the cylinder blocks 15, 16 in parallel to the drive shaft 20 at radial positions centering on the drive shaft 20, and the cylinder bores 22, 22 of the pairs have double-headed pistons. 23 are slidably fitted. A swash plate 24 fixed to the drive shaft 20 is moored to the piston 23 by bearing means composed of a shoe 25, a pawl 26, and the like. A suction chamber 27 and a discharge chamber 28 are formed in the housings 18 and 19, respectively.
2, and is also connected to an external refrigeration circuit via a suction hole and a discharge hole (not shown). Although not shown, check valves are provided at the suction port 29 and the discharge port 30, respectively.
The swash plate 24 is made of a non-magnetic material such as an Al--Si alloy, and a detected portion 31 according to the present invention is provided at an appropriate location on its outer peripheral surface. In the embodiment shown in FIG. 6, the detected portion 31 is the swash plate 24
However, in the embodiment shown in FIGS. 7 and 8 in which only the swash plate 24a portion is illustrated, the swash plate 24a On the outer circumferential surface of the swash plate 24a whose inclination angle is 0 (perpendicular to the axis of the drive shaft 20), that is, at the center of the axial direction of the swash plate 24a, when viewed in the radial direction,
Two detected portions 31a according to the present invention are provided. An electromagnetic sensor 32 having a configuration similar to that of the previously described embodiment is disposed on the outer shell of the cylinder block 16 so as to face a part of the periodic motion locus of the detected portion 31. The output terminal of the surrounding coil 34 is connected to the first
As shown in Figure 1, it is connected to a pulse presence/absence detector via an amplifier.

In the device of this embodiment configured as described above, when driving force is transmitted to the drive shaft 20 via a transmission device such as a clutch, the piston 23 reciprocates within the cylinder bore 22 due to the rotational force of the swash plate 24. The refrigerant introduced into the suction chamber 27 from the suction side of the external refrigeration circuit by the action of the reciprocating movement flows through the suction port 2.
9 into the cylinder bore 22, where it is compressed and then sent out to the discharge side of the external refrigeration circuit through the discharge port 30 and the discharge chamber 28, where the compressor performs its original function. 31 rotates around the axis of the drive shaft 20 and periodically faces the end face of the magnet 33 of the electromagnetic sensor 32, so that it is rotated by the electromotive force generated in the coil 34 in the same manner as in the previously described embodiment. As a result, a pulse as shown in FIG. 9 is generated at the output terminal of the coil 34.
Note that in the embodiments shown in FIGS. 7 and 8, pulse signals can be obtained at twice the frequency. The pulse signal obtained in this way is input to the pulse presence/absence detector via an amplifier, but no control operation is performed while the pulse signal is present.
Compressor operation continues. Next, when the compressor becomes unable to rotate due to damage to parts or a seizure accident, the detected part 3 for the electromagnetic sensor 32
1 is eliminated, and the pulse signal as described above can no longer be obtained. When the pulse presence/absence detector detects that the pulse signal disappears, it issues a disconnection command to the clutch and disconnects it from the power source to protect the transmission and prevent any negative effects on the power source itself. be able to. At this time, in the case where the transmission device is composed of a belt and this single belt is designed to drive auxiliary equipment such as a water pump or an oil generator, the belt may be broken. It is also possible to prevent serious vehicle accidents caused by overheating of the prime mover. In addition, if the configuration is such that a command to disengage the clutch is issued when the pulse signal is compared with that during normal operation and determined to be abnormal, the driving force can be cut off immediately before the compressor seizes or the like occurs. In this case, the compressor itself can also be protected.

In addition, in the present invention, since the detected portion is provided on the swash plate and temperature-sensitive ferrite is used as the magnetic material particles 6, the swash plate and the shoe are in a severe sliding condition as described above, so that the swash plate and the shuttle can be lubricated. Even if seizure occurs due to shortage, abnormal temperature rise of the swash plate due to abnormal sliding (boundary contact) is detected in advance and the driving force to the compressor is reliably cut off before seizure occurs. be able to. That is, in this case, the temperature-sensitive ferrite particles (particle size of 0.3 mm to 0.4 mm) in the previous stage, which are generally obtained by sintering the temperature-sensitive ferrite material, are used as they are, and the same method as in the above-mentioned embodiments is used. The detected part can be obtained by In this case, during normal operation (relatively low temperature), the temperature-sensitive ferrite acts as a magnetic material, and the same control as described above is possible; next, when the compressor temperature rises abnormally, In this case, the temperature of the detected part also rises and the temperature-sensitive ferrite becomes non-magnetic (temperature-sensitive ferrite particles are selected in advance whose Curie temperature almost matches the allowable temperature increase limit of the compressor). .)For,
Since the electromagnetic sensor cannot obtain a pulse signal, the driving force of the compressor is cut off by the same function as described above, and it is possible to prevent a seizure accident of the compressor.

As described above, according to the present invention, there is a detected part made of a magnetic material embedded in the surface of a member made of a non-magnetic material and which performs periodic motion, and a part of the detected part made of a non-magnetic material that faces a part of the periodic motion trajectory of the detected part. When configuring a compressor operation detection device using the installed electromagnetic sensor,
A recessed hole portion with one end open is bored in the surface of the member that performs periodic motion, a bulge is formed on the side wall of the recessed hole portion other than the position of the opening, and a magnetic material is placed in the recessed hole portion. A fluid containing particles and a binder is poured into the recessed hole to almost the same height as the opening position and is filled and fixed to form the detected part, so that it is not possible to deform the base material as in press fitting. In addition, even if there is a difference in thermal expansion coefficient between the base material and the magnetic material particles themselves, this difference will be absorbed by the binder and the difference between the base material and the base material will be reduced. Separation is difficult to occur, air is not sealed and left in the recessed hole, and the bulging part prevents the detection part from falling off, thereby preventing the compressor from malfunctioning. In addition, the protruding portion of the detected part can be easily finished.With these features, the device of the present invention can be easily obtained, and it can be used with high durability and reliability. In addition, since temperature-sensitive ferrite particles are used as magnetic material particles, the temperature-sensitive ferrite particles in the stage prior to obtaining the temperature-sensitive ferrite material in a cohesive state can be used as they are, making it easier to manufacture. The purpose is to reduce costs, eliminate the risk of damage, and in addition to controlling only based on the operating status of the compressor, detect the temperature status of the swash plate of the compressor to prevent seizure between the swash plate and the shuttle. It has the advantage that it can also be controlled in a controlled manner.

[Brief explanation of drawings]

1 to 10 show embodiments of the present invention, FIG. 1 is a partially sectional front view showing one embodiment of the invention, and FIG. 2 is a front view showing another embodiment. 3 to 5 are sectional views showing essential parts of various embodiments, FIG. 6 is a sectional front view showing one embodiment applied to a swash plate type compressor, and FIG. 7 is a sectional view showing another example. FIG. 8 is a partial front view showing the embodiment of FIG.
9 is a graph showing pulses obtained by an electromagnetic sensor, and FIG. 11 is an enlarged view showing a conventional device. 1...Rotating member, 3, 31, 31a, 36...
Detected part, 4... Recessed hole part, 5... Binding fixing agent, 6
...magnetic material particles, 7,32 ...electromagnetic sensor, 9,
33...Magnet, 11,34...Coil, 15,1
6...Cylinder block, 17...Valve plate, 18,
19... Housing, 20... Drive shaft, 22...
Cylinder bore, 23...piston, 24...swash plate, 27...suction chamber, 28...discharge chamber.

Claims (1)

[Claims] 1. A swash plate compressor in which a piston moored to a swash plate fixed to a drive shaft at an angle reciprocates within a cylinder bore as the swash plate rotates to perform a compression action. A recessed hole with one end open is formed in the outer peripheral surface of the swash plate which is made of a magnetic material and moves periodically, and a bulge is formed on a side wall of the recessed hole other than the opening, and A fluid containing magnetic material particles and a binder is poured into the recessed hole to almost the same height as the opening position of the recessed hole, and the fluid is filled and fixed to form a detected part, and the periodic movement of the detected part is fixed. An operation detection device for a swash plate compressor, characterized in that an electromagnetic sensor is arranged at a position facing a part of the locus. 2. The device according to claim 1, wherein the magnetic material particles are iron particles. 3. The device according to claim 1, wherein the magnetic material particles are temperature-sensitive ferrite particles. 4. The electromagnetic sensor includes a bar-shaped magnet whose end face faces a part of the periodic motion locus of the detected part;
2. The device according to claim 1, comprising a coil surrounding the side surface of the magnet and having an output terminal, and a main body portion that integrally fixes and holds both of the coils.