CN1193179A

CN1193179A - Multipole electron tube

Info

Publication number: CN1193179A
Application number: CN98104101A
Authority: CN
Inventors: 大贯博文; 村幸夫
Original assignee: Toshiba Corp
Current assignee: Canon Electron Tubes and Devices Co Ltd
Priority date: 1997-01-09
Filing date: 1998-01-09
Publication date: 1998-09-16
Anticipated expiration: 2018-01-09
Also published as: KR19980070512A; KR100281393B1; TW403929B; CN1108624C; JPH10255672A

Abstract

It enables to provide a multiple-pole electronic tube providing an actuation feature of voltage amplifying rate with less deviation in action and high quality.This invention of screw shape winding multiple-pole electronic tube consisting of cathode filament 23 with screw shape winding direction and grid pole 24 with a lateral held winding 26 which is curled oppositely to each other at screw winding direction.

Description

Computron

The present invention relates to have the helical form direct-heated cathode, the computron of at least one mouse-cage type control grid electrode and tubular anode.

A kind of for example transmitting tube of computron has: launch thermionic negative electrode; Seizure is from the thermionic tubular anode of this cathode emission; And at least one control grid electrode of the control hot electron throughput that between this negative electrode and anode, disposes.And general the employing is rolled into spiral helicine directly-heated filament to the metal wire that is made of thorium tungsten as negative electrode.In addition, general adopt many molybdenum fine rules on the promptly parallel direction of longitudinal direction with tubular axis side by side, and weld with the cross-brace line of reeling, with the mouse-cage type gate electrode that fetters these ordinates as control grid electrode.

In real public clear 38-2768 communique and real public clear 41-16896 communique, at length disclosed the structure of this computron.That is to say, shown in Fig. 3 (a) and (b), (c), the spiral helicine direct-heated cathode 112 of fixed support is housed on the negative electrode pillar 111 that disposes on the tubular axis in the structure that discloses in the last communique.And, around this negative electrode 112, dispose control grid electrode 113 coaxially.Control grid electrode 113 has many ordinates 114 that are made of the tungsten fine rule; Thicker is rolled into helical form to tie the cross-brace line 115 of these ordinates.Cross-brace line 115 is metal wires thicker than ordinate 114, with ordinate in the welding of intersection point place, the function that has fixed support ordinate mechanically and prevent to be out of shape.And the tubular anode 116 of the part of these filaments and gate electrode and double as vacuum tank is surrounded in configuration.

On the other hand, the above-mentioned latter, promptly the structure that discloses on real public clear 41-16896 communique as shown in Figure 4, is the structure that many cross-brace lines 115 are reeled on the vertical direction with respect to tubular axis.This structure is owing to prepare to press the cross-brace line 115 of predetermined diameter Cheng Yuan, and with after the predetermined space embedding, necessary each intersection point of welding is so exist the defective of making complexity around ordinate.

Therefore, above-mentioned the former structure, because cross-brace line 115 each intersection point of back welding about one or two of around ordinate, reeling continuously, so manufacturing is relatively simplified.But, as shown in Figure 3, prior art is that the helical form coiling direction of negative electrode 112 is identical with the helical form coiling direction of the cross-brace line of gate electrode, simultaneously, the pitch interval (Pf) of the helical coil of negative electrode 112 coiling equates with pitch interval (Ps) that the helical coil of the cross-brace line of gate electrode winds the line or about equally.

According to existing structure, as shown in Figure 5 and Figure 6, according to the helical coil coiling of negative electrode 112 and the helical coil coiling of the cross-brace line of gate electrode, the coincidence situation of on the direction of advance of thermionic current, roughly seeing from the just laterally direction of correspondence, operating characteristic, particularly voltage amplification degree (μ) change significantly, shown in dotted line (R).

That is to say that (5a) of Fig. 5 just is illustrated in horizontal direction promptly when the tubular axis vertical direction is seen the helical form coiling of cross-brace line 115 of the helical form coiling of negative electrode 112 and gate electrode, the pattern of situation is just assembled in two coilings with overlap condition.This situation is that to misunderstand bit interval (G) from the just laterally direction of the coiling of the cross-brace line 115 of the spiral of negative electrode 112 and gate electrode be zero (G=0).

Because the electron tube of assembling has suppressed to pass through from the thermionic of cathode emission with the cross-brace line 115 of gate electrode so the biglyyest, so its voltage amplification degree (μ) is the minimum voltage magnification ratio (μ) corresponding with characteristic transverse axis (G=0) shown in Figure 6, in three utmost point transmitting tubes of trial-production, μ=17.The ad-hoc location of the circumferencial direction of the negative electrode 112 of this state is assumed to Y, and the same ad-hoc location of gate electrode is Z, represents with Fig. 5.

Below, remaining untouched in the position of (5b) expression negative electrode 112 of Fig. 5, makes gate electrode 113 see the situation of revolving the position that turn 90 degrees in the clockwise direction and determining, assembling from the top.Therefore, the above-mentioned ad-hoc location Y of corresponding negative electrode 112, the ad-hoc location Z of gate electrode are in the position of enterprising clockwise 90 degree.In this case, the dislocation interval (G) and two spiral pitch interval (Pf, 1/4 suitable (G=0.25Pf) Ps) in abutting connection with spiral of the cross-brace line 115 of the spiral of negative electrode 112 and gate electrode.And the voltage amplification degree of Zu Zhuan electron tube (μ) is corresponding with the transverse axis (G=0.25) of Fig. 6 like this, μ=20.

And, shown in Fig. 5 (5c), corresponding with the ad-hoc location Y of negative electrode 112, under the situation of the position assembling of the ad-hoc location Z of gate electrode 113 being advanced in the clockwise direction 180 degree, dislocation interval and two spiral pitch interval (Pf, 1/2 suitable (G=0.5Pf) Ps) of two spirals.And the voltage amplification degree of Zu Zhuan electron tube (μ) is corresponding with the transverse axis (G=0.5) of Fig. 6 like this, μ=24.

Thus, in the existing structure that the helical form coiling direction of the cross-brace line of screw winding direction that makes negative electrode and gate electrode is reeled with equidirectional, the dislocation of the coiling by adjusting both is (G) at interval, can be though have with the advantage of the operating characteristic (voltage amplification degree μ) of setting electron tube to a certain degree arbitrarily, but in a large amount of productions of same electron tube, as long as the circumferencial direction of negative electrode and gate electrode allocation really misplaces slightly, characteristic is just discrete, the disadvantageous situation of inconsistent electron tube can occur making.Therefore, on the good consistent electron tube of a large amount of production qualities, there is obstacle.

The objective of the invention is to eliminate inappropriate situation of above-mentioned existing structure, in a large amount of productions with a kind of electron tube, assemble even concern under the unfixed situation in the position of the circumferencial direction of negative electrode and gate electrode, also can make the discrete less of operating characteristic, particularly voltage amplification degree (μ), provide quality good consistent computron.

According to the present invention is such computron, comprise: the direct-heated cathode that be used for emitting electrons of metal wire by predetermined pitch helically coiling, the periphery of this negative electrode configuration at least one have many grid ordinates and helical coil around be fixed on simultaneously on this grid ordinate the gate electrode of cross-brace line, with the tubular anode that is provided with in the periphery of gate electrode, wherein the cross-brace line of gate electrode is reeled along the direction helically opposite with the helical form coiling direction of negative electrode.

In addition, computron of the present invention is characterised in that the pitch interval (Ps) of the helical coil coiling of the cross-brace line of gate electrode is more than 0.8 times of pitch interval (Pf) of the helical coil coiling of negative electrode.

Have, computron of the present invention is characterised in that the cross-brace line of negative electrode and gate electrode all is made of single-wire respectively again.

Also have, computron of the present invention is characterised in that the ratio (Ds/Df) of the diameter (Df) of the diameter (Ds) of the cross-brace line of gate electrode and the metal wire of negative electrode is below 0.8.

Fig. 1 is the longitudinal sectional drawing of the electronic tubular construction that spirality negative electrode and mouse-cage type gate electrode are arranged of expression embodiment of the invention employing.

Fig. 2 is the enlarged drawing of the major part of the negative electrode of expression electron tube shown in Figure 1 and gate electrode.

Fig. 3 is the summary construction diagram of known electron tube one example of expression prior art.

Fig. 4 is the longitudinal sectional drawing of another routine major part of the known electron tube of expression prior art.

Fig. 5 is the ideograph that the coiling of negative electrode and the cross-brace line of gate electrode concerns in the expression electron tube shown in Figure 3.

Fig. 6 is the curve chart of variation characteristic of the voltage amplification degree of comparison diagram 1 and electron tube shown in Figure 3.

Below, with reference to accompanying drawing, describe embodiments of the invention in detail.

Fig. 1 is illustrated in the such high-frequency induction heating apparatus of for example high frequency fused equipment, three utmost point transmitting tubes such as the higher-order of oscillation output services characteristic that 30MHz, 6kW are arranged, and uses embodiments of the invention.The insulating concrete cylinder 12 of this transmitting tube by being made by pottery on negative electrode stem stem 11 is with cylindric anode 13 airtight joints of copper of the part of double as vacuum tank.On this anode 13, fixing fin 14, blast pipe 15, vent pipe protection cap 16.

On negative electrode stem stem 11, fixing a pair of

cathode terminal

17,18 and gate electrode terminal 19 electrically insulated from one another.On a cathode terminal 17, fix filament supports and be used to supply with the bar-shaped centre strut 21 of heating current, on another cathode terminal 18, fixing same side pillar 22.And, at such each fore-end of pair of

posts

21,22, respectively by welding, electricity and mechanically is connected also each fore-end 23a, 23b of being used to launch thermionic direct-heated cathode 23 of support helix shape coiling.

Around negative electrode 23, keep the cylindric gate electrode 24 of coaxial shape ground, predetermined space ground configuration mouse-cage type.This gate electrode 24 has many grid ordinates of arranging by predetermined space on predetermined radius predetermined circumference 25; Reel with helically around this grid ordinate and with the cross-brace line 26 of the intersection point welding of each ordinate 25.Gate electrode 24, its diagram bottom is fixed on the grid support cylinder 27, and its diagram upper end is fixed on the grid support ring 28.Have, grid support cylinder 27 is fixed on the gate electrode terminal board 19 of negative electrode stem stem 11 again.

Fig. 2 is the enlarged drawing of the major part of negative electrode and gate electrode.Negative electrode 23 is that diameter (Df) is the tungsten that contains trace thorium (Th) (W) alloy wire about 1mm.Shown in this figure (a), it be configured in a centre strut 21 on the central shaft around, it is rolled into the spiral of pre-fixing turn with predetermined spiral external diameter (Rf), predetermined pitch interval (Pf).Have again,, for example in 8 to 10 scope, can set the number of turns (Nf) of this negative electrode 23 arbitrarily by the characteristic of transmitting tube requirement.

Shown in Fig. 2 (b), on the circumference of the circle of pressing predetermined radii (Rs) regulation with the arranged spaced grid ordinate 25 of for example 24 five equilibriums, the cross-brace line 26 of reeling spirally in the opposite direction in the screw winding side of the periphery upper edge of these ordinates and negative electrode 23, thus constitute gate electrode 24.And, connect the intersection point of each grid ordinate 25 and cross-brace line 26 with welding for example.

The ordinate 25 of this gate electrode is that diameter for example is the molybdenum wire of 0.4mm, and cross-brace line 26 is that diameter is for example identical with ordinate 25 or be the identical molybdenum wire in its 1.0 to 2.0 times of scopes.In addition, do not wish to hinder more the throughput of electron beam, the ratio (Ds/Df) of the diameter (Df) of the diameter (Ds) of the cross-brace line of therefore selected gate electrode and the metal wire of negative electrode makes it below 0.8, better below 0.5.

In addition, the helical form coiling direction of the cross-brace line 26 of this gate electrode is opposite with the helical form coiling direction of negative electrode 23.And, remaining to not wishing to hinder more the throughput of electron beam, the intervals (Ps) of the helical coil coiling of this cross-brace line 26 is more than 0.8 times of helical coil coiling intervals (Pf) of negative electrode 23, better more than 1.0 times.

According to this embodiment, from just horizontal direction, the helical coil coiling of negative electrode 23 overlaps the quantity at place with the cross-brace line 26 of gate electrode, and roughly the degree of misalignment with the circumferencial direction of this filament and gate electrode has nothing to do.But, even there is dislocation in the assembling position of filament and gate electrode, roughly certain from the hot electron of cathode emission at the probability that towards the stroke of anode, stops because of gate electrode, compare with the characteristic (R) under the situation of the existing structure of Fig. 6, voltage amplification degree under the embodiment of the invention situation (μ) is basic to keep certain, shown in symbol among Fig. 6 (T), μ ≈ 23, it disperses and also becomes equal substantially.

Therefore, consistent even negative electrode and the position of the circumferencial direction of gate electrode can not overlap accurately when a large amount of assembly computron, also can obtain the particularly characteristic of voltage amplification degree (μ) of roughly uniform operating characteristic.Therefore, can simplify the assembly technology of electron tube.

Have, even this invention is used for disposing coaxially the computron of two above grids, the structure of its at least one gate electrode is if by above-mentioned formation, then can enjoy above-mentioned advantage again.

And the negative electrode of the foregoing description is wound into a spiral wire and constitutes, but is not limited to this, also can constitute the structure of the double helix shape line shown in Fig. 3 (b).In addition, the cross-brace line of gate electrode also is not limited to single line and reels, also can shown in Fig. 3 (c), reel with two-wire, or with the coil of wire more than the double joint around.But under such situation, the winding spacing of the cross-brace line of negative electrode or grid at interval (Pf, Ps) is used from the mean value definition of the intervals of the winding line of the adjacency of its whole abeam direction that contains winding line under each situation.And, the winding spacing under the situation that as depicted in figs. 1 and 2 single line is reeled at interval (Pf or Ps) also by the mean value definition of the intervals of whole winding line.

As mentioned above, according to this invention, because the coiling direction of negative electrode spiral is different with the screw winding direction of the cross-brace line of gate electrode, so no matter the dislocation size of the circumferencial direction of negative electrode and gate electrode how, all can obtain particularly voltage amplification degree of roughly certain operating characteristic.Thereby, the electron tube of discrete little, the unanimity best in quality of can be at low cost a large amount of production work characteristics.

Claims

1. computron comprises: the direct-heated cathode that is used for emitting electrons (2 3) that metal wire is wound into by the predetermined pitch helically; At least one of the periphery of this negative electrode configuration have many grid ordinates (25) and helical coil around and be fixed on the gate electrode (24) of the cross-brace line (26) on this grid ordinate; Tubular anode (13) with being provided with in the periphery of described gate electrode is characterized in that, the cross-brace line (26) of described gate electrode is reeled along the direction helically opposite with the helical form coiling direction of described negative electrode (23).

2. computron as claimed in claim 1 is characterized in that, the intervals (Ps) of the helical coil coiling of the cross-brace line (26) of described gate electrode is more than 0.8 times of intervals (Pf) of the helical coil coiling of described negative electrode (23).

3. computron as claimed in claim 1 is characterized in that, the cross-brace line (26) of described negative electrode (23) and described gate electrode all constitutes with single-wire respectively.

4. computron as claimed in claim 1 is characterized in that, the diameter (Ds) of the cross-brace line (26) of described gate electrode is below 0.8 with the ratio (Ds/Df) of the diameter (Df) of the metal wire of described negative electrode (23).